Merge pull request #1517 from 0xProject/feature/bignumber-8.0

Bignumber 8.0

128 files changed, 763 insertions, 364 deletions

diff --git a/contracts/examples/CHANGELOG.json b/contracts/examples/CHANGELOG.json
index 6adebc471..724ab1e4a 100644
--- a/contracts/examples/CHANGELOG.json
+++ b/contracts/examples/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.6",
         "changes": [
diff --git a/contracts/examples/package.json b/contracts/examples/package.json
index e95017eb1..845ea0636 100644
--- a/contracts/examples/package.json
+++ b/contracts/examples/package.json
@@ -45,7 +45,7 @@
         "@types/yargs": "^10.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereumjs-abi": "0.6.5",
         "make-promises-safe": "^1.1.0",
diff --git a/contracts/extensions/CHANGELOG.json b/contracts/extensions/CHANGELOG.json
index 0accc3475..920fef05a 100644
--- a/contracts/extensions/CHANGELOG.json
+++ b/contracts/extensions/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.2.3",
         "changes": [
diff --git a/contracts/extensions/package.json b/contracts/extensions/package.json
index a67b7645b..14492af8f 100644
--- a/contracts/extensions/package.json
+++ b/contracts/extensions/package.json
@@ -57,7 +57,7 @@
         "@types/yargs": "^10.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereumjs-abi": "0.6.5",
         "make-promises-safe": "^1.1.0",
diff --git a/contracts/extensions/test/extensions/balance_threshold_filter.ts b/contracts/extensions/test/extensions/balance_threshold_filter.ts
index a1c322e08..adeb7c422 100644
--- a/contracts/extensions/test/extensions/balance_threshold_filter.ts
+++ b/contracts/extensions/test/extensions/balance_threshold_filter.ts
@@ -269,7 +269,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -278,13 +278,13 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
             );
         });
         it('should revert if the Exchange transaction function is not supported', async () => {
@@ -357,7 +357,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -367,7 +367,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid),
@@ -378,14 +378,14 @@ describe(ContractName.BalanceThresholdFilter, () => {
             );
 
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount.times(2)),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount.times(2)),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.times(2).add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.times(2).plus(takerFeePaid)),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -461,7 +461,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -471,7 +471,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid),
@@ -482,14 +482,14 @@ describe(ContractName.BalanceThresholdFilter, () => {
             );
 
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount.times(2)),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount.times(2)),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.times(2).add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.times(2).plus(takerFeePaid)),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -559,7 +559,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -569,7 +569,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid),
@@ -580,14 +580,14 @@ describe(ContractName.BalanceThresholdFilter, () => {
             );
 
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount.times(2)),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount.times(2)),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.times(2).add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.times(2).plus(takerFeePaid)),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -658,7 +658,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -667,13 +667,13 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
             );
         });
         it('should revert if maker does not meet the balance threshold', async () => {
@@ -736,7 +736,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -745,13 +745,13 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
             );
         });
         it('should revert if maker does not meet the balance threshold', async () => {
@@ -811,7 +811,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount_),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount_),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(makerFeePaid),
@@ -820,13 +820,13 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount_),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
             );
         });
         it('should revert if maker does not meet the balance threshold', async () => {
@@ -904,7 +904,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(validSignedOrder.makerAssetAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(validSignedOrder.takerAssetAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(validSignedOrder.takerAssetAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(validSignedOrder.makerFee),
@@ -914,7 +914,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount2),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid2),
@@ -924,7 +924,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(cumulativeTakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(cumulativeMakerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(cumulativeMakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
@@ -932,9 +932,9 @@ describe(ContractName.BalanceThresholdFilter, () => {
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[feeRecipientAddress][zrxToken.address]
-                    .add(validSignedOrder.makerFee)
-                    .add(makerFeePaid2)
-                    .add(takerFeePaid),
+                    .plus(validSignedOrder.makerFee)
+                    .plus(makerFeePaid2)
+                    .plus(takerFeePaid),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -1008,7 +1008,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(validSignedOrder.makerAssetAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(validSignedOrder.takerAssetAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(validSignedOrder.takerAssetAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(validSignedOrder.makerFee),
@@ -1018,7 +1018,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount2),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid2),
@@ -1028,7 +1028,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(cumulativeTakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(cumulativeMakerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(cumulativeMakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
@@ -1036,9 +1036,9 @@ describe(ContractName.BalanceThresholdFilter, () => {
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[feeRecipientAddress][zrxToken.address]
-                    .add(validSignedOrder.makerFee)
-                    .add(makerFeePaid2)
-                    .add(takerFeePaid),
+                    .plus(validSignedOrder.makerFee)
+                    .plus(makerFeePaid2)
+                    .plus(takerFeePaid),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -1104,7 +1104,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(validSignedOrder.makerAssetAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(validSignedOrder.takerAssetAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(validSignedOrder.takerAssetAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(validSignedOrder.makerFee),
@@ -1114,7 +1114,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount2),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid2),
@@ -1124,7 +1124,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(cumulativeTakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(cumulativeMakerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(cumulativeMakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
@@ -1132,9 +1132,9 @@ describe(ContractName.BalanceThresholdFilter, () => {
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[feeRecipientAddress][zrxToken.address]
-                    .add(validSignedOrder.makerFee)
-                    .add(makerFeePaid2)
-                    .add(takerFeePaid),
+                    .plus(validSignedOrder.makerFee)
+                    .plus(makerFeePaid2)
+                    .plus(takerFeePaid),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -1210,7 +1210,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress][defaultMakerAssetAddress].minus(validSignedOrder.makerAssetAmount),
             );
             expect(newBalances[validMakerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress][defaultTakerAssetAddress].add(validSignedOrder.takerAssetAmount),
+                erc20Balances[validMakerAddress][defaultTakerAssetAddress].plus(validSignedOrder.takerAssetAmount),
             );
             expect(newBalances[validMakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress][zrxToken.address].minus(validSignedOrder.makerFee),
@@ -1220,7 +1220,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validMakerAddress2][defaultMakerAssetAddress].minus(makerAssetFillAmount2),
             );
             expect(newBalances[validMakerAddress2][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[validMakerAddress2][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[validMakerAddress2][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validMakerAddress2][zrxToken.address].minus(makerFeePaid2),
@@ -1230,7 +1230,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 erc20Balances[validTakerAddress][defaultTakerAssetAddress].minus(cumulativeTakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(cumulativeMakerAssetFillAmount),
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(cumulativeMakerAssetFillAmount),
             );
             expect(newBalances[validTakerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address].minus(takerFeePaid),
@@ -1238,9 +1238,9 @@ describe(ContractName.BalanceThresholdFilter, () => {
             // Fee recipient
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[feeRecipientAddress][zrxToken.address]
-                    .add(validSignedOrder.makerFee)
-                    .add(makerFeePaid2)
-                    .add(takerFeePaid),
+                    .plus(validSignedOrder.makerFee)
+                    .plus(makerFeePaid2)
+                    .plus(takerFeePaid),
             );
         });
         it('should revert if one maker does not meet the balance threshold', async () => {
@@ -1329,7 +1329,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 newBalances[signedOrderLeft.makerAddress][defaultMakerAssetAddress],
                 'Checking left maker egress ERC20 account balance',
             ).to.be.bignumber.equal(
-                erc20Balances[signedOrderLeft.makerAddress][defaultMakerAssetAddress].sub(
+                erc20Balances[signedOrderLeft.makerAddress][defaultMakerAssetAddress].minus(
                     expectedTransferAmounts.amountSoldByLeftMaker,
                 ),
             );
@@ -1337,7 +1337,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 newBalances[signedOrderRight.makerAddress][defaultTakerAssetAddress],
                 'Checking right maker ingress ERC20 account balance',
             ).to.be.bignumber.equal(
-                erc20Balances[signedOrderRight.makerAddress][defaultTakerAssetAddress].sub(
+                erc20Balances[signedOrderRight.makerAddress][defaultTakerAssetAddress].minus(
                     expectedTransferAmounts.amountSoldByRightMaker,
                 ),
             );
@@ -1345,7 +1345,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 newBalances[validTakerAddress][defaultMakerAssetAddress],
                 'Checking taker ingress ERC20 account balance',
             ).to.be.bignumber.equal(
-                erc20Balances[validTakerAddress][defaultMakerAssetAddress].add(
+                erc20Balances[validTakerAddress][defaultMakerAssetAddress].plus(
                     expectedTransferAmounts.amountReceivedByTaker,
                 ),
             );
@@ -1353,7 +1353,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 newBalances[signedOrderLeft.makerAddress][defaultTakerAssetAddress],
                 'Checking left maker ingress ERC20 account balance',
             ).to.be.bignumber.equal(
-                erc20Balances[signedOrderLeft.makerAddress][defaultTakerAssetAddress].add(
+                erc20Balances[signedOrderLeft.makerAddress][defaultTakerAssetAddress].plus(
                     expectedTransferAmounts.amountBoughtByLeftMaker,
                 ),
             );
@@ -1361,7 +1361,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 newBalances[signedOrderRight.makerAddress][defaultMakerAssetAddress],
                 'Checking right maker egress ERC20 account balance',
             ).to.be.bignumber.equal(
-                erc20Balances[signedOrderRight.makerAddress][defaultMakerAssetAddress].add(
+                erc20Balances[signedOrderRight.makerAddress][defaultMakerAssetAddress].plus(
                     expectedTransferAmounts.amountBoughtByRightMaker,
                 ),
             );
@@ -1388,7 +1388,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
             ).to.be.bignumber.equal(
                 erc20Balances[validTakerAddress][zrxToken.address]
                     .minus(expectedTransferAmounts.feePaidByTakerLeft)
-                    .sub(expectedTransferAmounts.feePaidByTakerRight),
+                    .minus(expectedTransferAmounts.feePaidByTakerRight),
             );
             // Received fees
             expect(
@@ -1396,10 +1396,10 @@ describe(ContractName.BalanceThresholdFilter, () => {
                 'Checking left fee recipient ingress ERC20 account fees',
             ).to.be.bignumber.equal(
                 erc20Balances[feeRecipientAddress][zrxToken.address]
-                    .add(expectedTransferAmounts.feePaidByLeftMaker)
-                    .add(expectedTransferAmounts.feePaidByRightMaker)
-                    .add(expectedTransferAmounts.feePaidByTakerLeft)
-                    .add(expectedTransferAmounts.feePaidByTakerRight),
+                    .plus(expectedTransferAmounts.feePaidByLeftMaker)
+                    .plus(expectedTransferAmounts.feePaidByRightMaker)
+                    .plus(expectedTransferAmounts.feePaidByTakerLeft)
+                    .plus(expectedTransferAmounts.feePaidByTakerRight),
             );
         });
         it('should revert if left maker does not meet the balance threshold', async () => {
@@ -1595,7 +1595,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                     signedOrder,
                 );
                 const saltAsBigNumber = new BigNumber(salt);
-                if (saltAsBigNumber.lessThanOrEqualTo(cancelOrdersUpToThisSalt)) {
+                if (saltAsBigNumber.isLessThanOrEqualTo(cancelOrdersUpToThisSalt)) {
                     return expect(orderInfoAfterCancelling.orderStatus).to.be.equal(OrderStatus.Cancelled);
                 } else {
                     return expect(orderInfoAfterCancelling.orderStatus).to.be.equal(OrderStatus.Fillable);
@@ -1631,7 +1631,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
                     signedOrder,
                 );
                 const saltAsBigNumber = new BigNumber(salt);
-                if (saltAsBigNumber.lessThanOrEqualTo(cancelOrdersUpToThisSalt)) {
+                if (saltAsBigNumber.isLessThanOrEqualTo(cancelOrdersUpToThisSalt)) {
                     return expect(orderInfoAfterCancelling.orderStatus).to.be.equal(OrderStatus.Cancelled);
                 } else {
                     return expect(orderInfoAfterCancelling.orderStatus).to.be.equal(OrderStatus.Fillable);
diff --git a/contracts/extensions/test/utils/forwarder_wrapper.ts b/contracts/extensions/test/utils/forwarder_wrapper.ts
index 9e44ff6b9..4a43be04a 100644
--- a/contracts/extensions/test/utils/forwarder_wrapper.ts
+++ b/contracts/extensions/test/utils/forwarder_wrapper.ts
@@ -29,7 +29,7 @@ export class ForwarderWrapper {
                     feeOrder.takerAssetAmount
                         .times(remainingFeeAmount)
                         .dividedBy(feeAvailable)
-                        .ceil(),
+                        .integerValue(BigNumber.ROUND_CEIL),
                 );
                 remainingFeeAmount = new BigNumber(0);
             } else if (!remainingFeeAmount.isZero()) {
diff --git a/contracts/interfaces/CHANGELOG.json b/contracts/interfaces/CHANGELOG.json
index 6adebc471..724ab1e4a 100644
--- a/contracts/interfaces/CHANGELOG.json
+++ b/contracts/interfaces/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.6",
         "changes": [
diff --git a/contracts/libs/CHANGELOG.json b/contracts/libs/CHANGELOG.json
index 6adebc471..724ab1e4a 100644
--- a/contracts/libs/CHANGELOG.json
+++ b/contracts/libs/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.6",
         "changes": [
diff --git a/contracts/libs/package.json b/contracts/libs/package.json
index 2429c8aed..b28ec3774 100644
--- a/contracts/libs/package.json
+++ b/contracts/libs/package.json
@@ -56,7 +56,7 @@
         "@types/yargs": "^10.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereumjs-abi": "0.6.5",
         "make-promises-safe": "^1.1.0",
diff --git a/contracts/multisig/CHANGELOG.json b/contracts/multisig/CHANGELOG.json
index 6adebc471..724ab1e4a 100644
--- a/contracts/multisig/CHANGELOG.json
+++ b/contracts/multisig/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.6",
         "changes": [
diff --git a/contracts/multisig/package.json b/contracts/multisig/package.json
index 683bb85d4..1c3911cbc 100644
--- a/contracts/multisig/package.json
+++ b/contracts/multisig/package.json
@@ -57,7 +57,7 @@
         "@types/yargs": "^10.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^4.1.0",
diff --git a/contracts/protocol/CHANGELOG.json b/contracts/protocol/CHANGELOG.json
index f7401039a..0d513cc17 100644
--- a/contracts/protocol/CHANGELOG.json
+++ b/contracts/protocol/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "2.2.3",
         "changes": [
diff --git a/contracts/protocol/package.json b/contracts/protocol/package.json
index 87ee10e92..d1ef70a70 100644
--- a/contracts/protocol/package.json
+++ b/contracts/protocol/package.json
@@ -55,7 +55,7 @@
         "@types/yargs": "^10.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereumjs-abi": "0.6.5",
         "make-promises-safe": "^1.1.0",
diff --git a/contracts/protocol/test/asset_proxy/proxies.ts b/contracts/protocol/test/asset_proxy/proxies.ts
index bbb44f402..c34be9c6a 100644
--- a/contracts/protocol/test/asset_proxy/proxies.ts
+++ b/contracts/protocol/test/asset_proxy/proxies.ts
@@ -259,7 +259,7 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(amount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(amount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(amount),
                 );
             });
 
@@ -318,7 +318,7 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(amount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(amount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(amount),
                 );
             });
 
@@ -737,7 +737,7 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalAmount),
                 );
             });
             it('should dispatch an ERC20 transfer when input amount is 0', async () => {
@@ -800,7 +800,7 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalAmount),
                 );
             });
             it('should successfully transfer multiple different ERC20 tokens', async () => {
@@ -834,13 +834,13 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalErc20AAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalErc20AAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalErc20AAmount),
                 );
                 expect(newBalances[fromAddress][erc20TokenB.address]).to.be.bignumber.equal(
                     erc20Balances[fromAddress][erc20TokenB.address].minus(totalErc20BAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenB.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenB.address].add(totalErc20BAmount),
+                    erc20Balances[toAddress][erc20TokenB.address].plus(totalErc20BAmount),
                 );
             });
             it('should transfer a single ERC721 token', async () => {
@@ -970,7 +970,7 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalAmount),
                 );
                 const newOwnerFromAsset = await erc721TokenA.ownerOf.callAsync(erc721AFromTokenId);
                 expect(newOwnerFromAsset).to.be.equal(toAddress);
@@ -1008,7 +1008,7 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalAmount),
                 );
                 const newOwnerFromAsset = await erc721TokenA.ownerOf.callAsync(erc721AFromTokenId);
                 expect(newOwnerFromAsset).to.be.equal(toAddress);
@@ -1044,13 +1044,13 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalErc20AAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalErc20AAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalErc20AAmount),
                 );
                 expect(newBalances[fromAddress][erc20TokenB.address]).to.be.bignumber.equal(
                     erc20Balances[fromAddress][erc20TokenB.address].minus(totalErc20BAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenB.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenB.address].add(totalErc20BAmount),
+                    erc20Balances[toAddress][erc20TokenB.address].plus(totalErc20BAmount),
                 );
             });
             it('should successfully transfer a large amount of tokens', async () => {
@@ -1122,13 +1122,13 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[fromAddress][erc20TokenA.address].minus(totalErc20AAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenA.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenA.address].add(totalErc20AAmount),
+                    erc20Balances[toAddress][erc20TokenA.address].plus(totalErc20AAmount),
                 );
                 expect(newBalances[fromAddress][erc20TokenB.address]).to.be.bignumber.equal(
                     erc20Balances[fromAddress][erc20TokenB.address].minus(totalErc20BAmount),
                 );
                 expect(newBalances[toAddress][erc20TokenB.address]).to.be.bignumber.equal(
-                    erc20Balances[toAddress][erc20TokenB.address].add(totalErc20BAmount),
+                    erc20Balances[toAddress][erc20TokenB.address].plus(totalErc20BAmount),
                 );
             });
             it('should revert if a single transfer fails', async () => {
diff --git a/contracts/protocol/test/exchange/core.ts b/contracts/protocol/test/exchange/core.ts
index 700643b79..f88be1c94 100644
--- a/contracts/protocol/test/exchange/core.ts
+++ b/contracts/protocol/test/exchange/core.ts
@@ -538,7 +538,7 @@ describe('Exchange core', () => {
         it('should throw if order is expired', async () => {
             const currentTimestamp = await getLatestBlockTimestampAsync();
             signedOrder = await orderFactory.newSignedOrderAsync({
-                expirationTimeSeconds: new BigNumber(currentTimestamp).sub(10),
+                expirationTimeSeconds: new BigNumber(currentTimestamp).minus(10),
             });
             return expectTransactionFailedAsync(
                 exchangeWrapper.cancelOrderAsync(signedOrder, makerAddress),
@@ -625,15 +625,15 @@ describe('Exchange core', () => {
             });
 
             const newBalances = await erc20Wrapper.getBalancesAsync();
-            const fillMakerAssetAmount = signedOrders[2].makerAssetAmount.add(signedOrders[3].makerAssetAmount);
-            const fillTakerAssetAmount = signedOrders[2].takerAssetAmount.add(signedOrders[3].takerAssetAmount);
-            const makerFee = signedOrders[2].makerFee.add(signedOrders[3].makerFee);
-            const takerFee = signedOrders[2].takerFee.add(signedOrders[3].takerFee);
+            const fillMakerAssetAmount = signedOrders[2].makerAssetAmount.plus(signedOrders[3].makerAssetAmount);
+            const fillTakerAssetAmount = signedOrders[2].takerAssetAmount.plus(signedOrders[3].takerAssetAmount);
+            const makerFee = signedOrders[2].makerFee.plus(signedOrders[3].makerFee);
+            const takerFee = signedOrders[2].takerFee.plus(signedOrders[3].takerFee);
             expect(newBalances[makerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
                 erc20Balances[makerAddress][defaultMakerAssetAddress].minus(fillMakerAssetAmount),
             );
             expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[makerAddress][defaultTakerAssetAddress].add(fillTakerAssetAmount),
+                erc20Balances[makerAddress][defaultTakerAssetAddress].plus(fillTakerAssetAmount),
             );
             expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -642,13 +642,13 @@ describe('Exchange core', () => {
                 erc20Balances[takerAddress][defaultTakerAssetAddress].minus(fillTakerAssetAmount),
             );
             expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[takerAddress][defaultMakerAssetAddress].add(fillMakerAssetAmount),
+                erc20Balances[takerAddress][defaultMakerAssetAddress].plus(fillMakerAssetAmount),
             );
             expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
             );
         });
     });
diff --git a/contracts/protocol/test/exchange/dispatcher.ts b/contracts/protocol/test/exchange/dispatcher.ts
index 5b1ac1e20..eca1b38f1 100644
--- a/contracts/protocol/test/exchange/dispatcher.ts
+++ b/contracts/protocol/test/exchange/dispatcher.ts
@@ -205,7 +205,7 @@ describe('AssetProxyDispatcher', () => {
                 erc20Balances[makerAddress][zrxToken.address].minus(amount),
             );
             expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[takerAddress][zrxToken.address].add(amount),
+                erc20Balances[takerAddress][zrxToken.address].plus(amount),
             );
         });
 
diff --git a/contracts/protocol/test/exchange/internal.ts b/contracts/protocol/test/exchange/internal.ts
index 972f5efb6..6ff1fdc2f 100644
--- a/contracts/protocol/test/exchange/internal.ts
+++ b/contracts/protocol/test/exchange/internal.ts
@@ -90,14 +90,14 @@ describe('Exchange core internal functions', () => {
         if (target.eq(0)) {
             return false;
         }
-        const product = numerator.mul(target);
+        const product = numerator.multipliedBy(target);
         const remainder = product.mod(denominator);
-        const remainderTimes1000 = remainder.mul('1000');
+        const remainderTimes1000 = remainder.multipliedBy('1000');
         const isError = remainderTimes1000.gte(product);
-        if (product.greaterThan(MAX_UINT256)) {
+        if (product.isGreaterThan(MAX_UINT256)) {
             throw overflowErrorForCall;
         }
-        if (remainderTimes1000.greaterThan(MAX_UINT256)) {
+        if (remainderTimes1000.isGreaterThan(MAX_UINT256)) {
             throw overflowErrorForCall;
         }
         return isError;
@@ -117,15 +117,15 @@ describe('Exchange core internal functions', () => {
         if (target.eq(0)) {
             return false;
         }
-        const product = numerator.mul(target);
+        const product = numerator.multipliedBy(target);
         const remainder = product.mod(denominator);
-        const error = denominator.sub(remainder).mod(denominator);
-        const errorTimes1000 = error.mul('1000');
+        const error = denominator.minus(remainder).mod(denominator);
+        const errorTimes1000 = error.multipliedBy('1000');
         const isError = errorTimes1000.gte(product);
-        if (product.greaterThan(MAX_UINT256)) {
+        if (product.isGreaterThan(MAX_UINT256)) {
             throw overflowErrorForCall;
         }
-        if (errorTimes1000.greaterThan(MAX_UINT256)) {
+        if (errorTimes1000.isGreaterThan(MAX_UINT256)) {
             throw overflowErrorForCall;
         }
         return isError;
@@ -143,8 +143,8 @@ describe('Exchange core internal functions', () => {
         if (isRoundingError) {
             throw roundingErrorForCall;
         }
-        const product = numerator.mul(target);
-        if (product.greaterThan(MAX_UINT256)) {
+        const product = numerator.multipliedBy(target);
+        if (product.isGreaterThan(MAX_UINT256)) {
             throw overflowErrorForCall;
         }
         return product.dividedToIntegerBy(denominator);
@@ -177,8 +177,8 @@ describe('Exchange core internal functions', () => {
                 _.cloneDeep(totalFillResults),
                 singleFillResults,
                 (totalVal: BigNumber, singleVal: BigNumber) => {
-                    const newTotal = totalVal.add(singleVal);
-                    if (newTotal.greaterThan(MAX_UINT256)) {
+                    const newTotal = totalVal.plus(singleVal);
+                    if (newTotal.isGreaterThan(MAX_UINT256)) {
                         throw overflowErrorForCall;
                     }
                     return newTotal;
@@ -271,8 +271,8 @@ describe('Exchange core internal functions', () => {
             if (denominator.eq(0)) {
                 throw divisionByZeroErrorForCall;
             }
-            const product = numerator.mul(target);
-            if (product.greaterThan(MAX_UINT256)) {
+            const product = numerator.multipliedBy(target);
+            if (product.isGreaterThan(MAX_UINT256)) {
                 throw overflowErrorForCall;
             }
             return product.dividedToIntegerBy(denominator);
@@ -301,16 +301,16 @@ describe('Exchange core internal functions', () => {
             if (denominator.eq(0)) {
                 throw divisionByZeroErrorForCall;
             }
-            const product = numerator.mul(target);
-            const offset = product.add(denominator.sub(1));
-            if (offset.greaterThan(MAX_UINT256)) {
+            const product = numerator.multipliedBy(target);
+            const offset = product.plus(denominator.minus(1));
+            if (offset.isGreaterThan(MAX_UINT256)) {
                 throw overflowErrorForCall;
             }
             const result = offset.dividedToIntegerBy(denominator);
             if (product.mod(denominator).eq(0)) {
-                expect(result.mul(denominator)).to.be.bignumber.eq(product);
+                expect(result.multipliedBy(denominator)).to.be.bignumber.eq(product);
             } else {
-                expect(result.mul(denominator)).to.be.bignumber.gt(product);
+                expect(result.multipliedBy(denominator)).to.be.bignumber.gt(product);
             }
             return result;
         }
@@ -358,16 +358,16 @@ describe('Exchange core internal functions', () => {
             if (isRoundingError) {
                 throw roundingErrorForCall;
             }
-            const product = numerator.mul(target);
-            const offset = product.add(denominator.sub(1));
-            if (offset.greaterThan(MAX_UINT256)) {
+            const product = numerator.multipliedBy(target);
+            const offset = product.plus(denominator.minus(1));
+            if (offset.isGreaterThan(MAX_UINT256)) {
                 throw overflowErrorForCall;
             }
             const result = offset.dividedToIntegerBy(denominator);
             if (product.mod(denominator).eq(0)) {
-                expect(result.mul(denominator)).to.be.bignumber.eq(product);
+                expect(result.multipliedBy(denominator)).to.be.bignumber.eq(product);
             } else {
-                expect(result.mul(denominator)).to.be.bignumber.gt(product);
+                expect(result.multipliedBy(denominator)).to.be.bignumber.gt(product);
             }
             return result;
         }
@@ -433,8 +433,8 @@ describe('Exchange core internal functions', () => {
             // tslint:disable-next-line:no-unused-variable
             orderHash: string,
         ): Promise<BigNumber> {
-            const totalFilledAmount = takerAssetFilledAmount.add(orderTakerAssetFilledAmount);
-            if (totalFilledAmount.greaterThan(MAX_UINT256)) {
+            const totalFilledAmount = takerAssetFilledAmount.plus(orderTakerAssetFilledAmount);
+            if (totalFilledAmount.isGreaterThan(MAX_UINT256)) {
                 throw overflowErrorForSendTransaction;
             }
             return totalFilledAmount;
diff --git a/contracts/protocol/test/exchange/transactions.ts b/contracts/protocol/test/exchange/transactions.ts
index 746f3cb04..e8c775f3e 100644
--- a/contracts/protocol/test/exchange/transactions.ts
+++ b/contracts/protocol/test/exchange/transactions.ts
@@ -160,7 +160,7 @@ describe('Exchange transactions', () => {
                     erc20Balances[makerAddress][defaultMakerTokenAddress].minus(makerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][defaultTakerTokenAddress]).to.be.bignumber.equal(
-                    erc20Balances[makerAddress][defaultTakerTokenAddress].add(takerAssetFillAmount),
+                    erc20Balances[makerAddress][defaultTakerTokenAddress].plus(takerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][zrxToken.address].minus(makerFeePaid),
@@ -169,13 +169,13 @@ describe('Exchange transactions', () => {
                     erc20Balances[takerAddress][defaultTakerTokenAddress].minus(takerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][defaultMakerTokenAddress]).to.be.bignumber.equal(
-                    erc20Balances[takerAddress][defaultMakerTokenAddress].add(makerAssetFillAmount),
+                    erc20Balances[takerAddress][defaultMakerTokenAddress].plus(makerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[takerAddress][zrxToken.address].minus(takerFeePaid),
                 );
                 expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                    erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                    erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
                 );
             });
 
@@ -234,7 +234,7 @@ describe('Exchange transactions', () => {
                     senderAddress: exchangeWrapperContract.address,
                     salt: orderSalt,
                 });
-                const targetOrderEpoch = orderSalt.add(1);
+                const targetOrderEpoch = orderSalt.plus(1);
                 const cancelData = exchange.cancelOrdersUpTo.getABIEncodedTransactionData(targetOrderEpoch);
                 const signedCancelTx = makerTransactionFactory.newSignedTransaction(cancelData);
                 await exchangeWrapperContract.cancelOrdersUpTo.sendTransactionAsync(
@@ -273,7 +273,7 @@ describe('Exchange transactions', () => {
                     senderAddress: exchangeWrapperContract.address,
                     salt: orderSalt,
                 });
-                const targetOrderEpoch = orderSalt.add(1);
+                const targetOrderEpoch = orderSalt.plus(1);
                 await exchangeWrapper.cancelOrdersUpToAsync(targetOrderEpoch, makerAddress);
 
                 erc20Balances = await erc20Wrapper.getBalancesAsync();
@@ -308,7 +308,7 @@ describe('Exchange transactions', () => {
                     erc20Balances[makerAddress][defaultMakerTokenAddress].minus(makerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][defaultTakerTokenAddress]).to.be.bignumber.equal(
-                    erc20Balances[makerAddress][defaultTakerTokenAddress].add(takerAssetFillAmount),
+                    erc20Balances[makerAddress][defaultTakerTokenAddress].plus(takerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][zrxToken.address].minus(makerFeePaid),
@@ -317,13 +317,13 @@ describe('Exchange transactions', () => {
                     erc20Balances[takerAddress][defaultTakerTokenAddress].minus(takerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][defaultMakerTokenAddress]).to.be.bignumber.equal(
-                    erc20Balances[takerAddress][defaultMakerTokenAddress].add(makerAssetFillAmount),
+                    erc20Balances[takerAddress][defaultMakerTokenAddress].plus(makerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[takerAddress][zrxToken.address].minus(takerFeePaid),
                 );
                 expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                    erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                    erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
                 );
             });
         });
@@ -444,7 +444,7 @@ describe('Exchange transactions', () => {
                 erc20Balances[makerAddress][defaultMakerTokenAddress].minus(makerAssetFillAmount),
             );
             expect(newBalances[makerAddress][defaultTakerTokenAddress]).to.be.bignumber.equal(
-                erc20Balances[makerAddress][defaultTakerTokenAddress].add(takerAssetFillAmount),
+                erc20Balances[makerAddress][defaultTakerTokenAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[makerAddress][zrxToken.address].minus(makerFeePaid),
@@ -453,13 +453,13 @@ describe('Exchange transactions', () => {
                 erc20Balances[takerAddress][defaultTakerTokenAddress].minus(takerAssetFillAmount),
             );
             expect(newBalances[takerAddress][defaultMakerTokenAddress]).to.be.bignumber.equal(
-                erc20Balances[takerAddress][defaultMakerTokenAddress].add(makerAssetFillAmount),
+                erc20Balances[takerAddress][defaultMakerTokenAddress].plus(makerAssetFillAmount),
             );
             expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[takerAddress][zrxToken.address].minus(takerFeePaid),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFeePaid.add(takerFeePaid)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFeePaid.plus(takerFeePaid)),
             );
         });
     });
diff --git a/contracts/protocol/test/exchange/wrapper.ts b/contracts/protocol/test/exchange/wrapper.ts
index 4c4506945..49ba5a2e5 100644
--- a/contracts/protocol/test/exchange/wrapper.ts
+++ b/contracts/protocol/test/exchange/wrapper.ts
@@ -189,7 +189,7 @@ describe('Exchange wrappers', () => {
                 erc20Balances[makerAddress][defaultMakerAssetAddress].minus(makerAssetFilledAmount),
             );
             expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[makerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[makerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -198,20 +198,20 @@ describe('Exchange wrappers', () => {
                 erc20Balances[takerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
             );
             expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[takerAddress][defaultMakerAssetAddress].add(makerAssetFilledAmount),
+                erc20Balances[takerAddress][defaultMakerAssetAddress].plus(makerAssetFilledAmount),
             );
             expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
             );
         });
 
         it('should throw if a signedOrder is expired', async () => {
             const currentTimestamp = await getLatestBlockTimestampAsync();
             const signedOrder = await orderFactory.newSignedOrderAsync({
-                expirationTimeSeconds: new BigNumber(currentTimestamp).sub(10),
+                expirationTimeSeconds: new BigNumber(currentTimestamp).minus(10),
             });
 
             return expectTransactionFailedAsync(
@@ -284,7 +284,7 @@ describe('Exchange wrappers', () => {
                 erc20Balances[makerAddress][defaultMakerAssetAddress].minus(makerAssetFilledAmount),
             );
             expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[makerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                erc20Balances[makerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
             );
             expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -293,13 +293,13 @@ describe('Exchange wrappers', () => {
                 erc20Balances[takerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
             );
             expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                erc20Balances[takerAddress][defaultMakerAssetAddress].add(makerAssetFilledAmount),
+                erc20Balances[takerAddress][defaultMakerAssetAddress].plus(makerAssetFilledAmount),
             );
             expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                 erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
             );
             expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
             );
         });
 
@@ -493,15 +493,15 @@ describe('Exchange wrappers', () => {
                     erc20Balances[makerAddress][makerAssetAddress] = erc20Balances[makerAddress][
                         makerAssetAddress
                     ].minus(makerAssetFilledAmount);
-                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][takerAssetAddress].add(
-                        takerAssetFillAmount,
-                    );
+                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][
+                        takerAssetAddress
+                    ].plus(takerAssetFillAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         makerFee,
                     );
-                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][makerAssetAddress].add(
-                        makerAssetFilledAmount,
-                    );
+                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][
+                        makerAssetAddress
+                    ].plus(makerAssetFilledAmount);
                     erc20Balances[takerAddress][takerAssetAddress] = erc20Balances[takerAddress][
                         takerAssetAddress
                     ].minus(takerAssetFillAmount);
@@ -510,7 +510,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(makerFee.add(takerFee));
+                    ].plus(makerFee.plus(takerFee));
                 });
 
                 await exchangeWrapper.batchFillOrdersAsync(signedOrders, takerAddress, {
@@ -562,15 +562,15 @@ describe('Exchange wrappers', () => {
                     erc20Balances[makerAddress][makerAssetAddress] = erc20Balances[makerAddress][
                         makerAssetAddress
                     ].minus(makerAssetFilledAmount);
-                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][takerAssetAddress].add(
-                        takerAssetFillAmount,
-                    );
+                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][
+                        takerAssetAddress
+                    ].plus(takerAssetFillAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         makerFee,
                     );
-                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][makerAssetAddress].add(
-                        makerAssetFilledAmount,
-                    );
+                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][
+                        makerAssetAddress
+                    ].plus(makerAssetFilledAmount);
                     erc20Balances[takerAddress][takerAssetAddress] = erc20Balances[takerAddress][
                         takerAssetAddress
                     ].minus(takerAssetFillAmount);
@@ -579,7 +579,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(makerFee.add(takerFee));
+                    ].plus(makerFee.plus(takerFee));
                 });
 
                 await exchangeWrapper.batchFillOrKillOrdersAsync(signedOrders, takerAddress, {
@@ -647,15 +647,15 @@ describe('Exchange wrappers', () => {
                     erc20Balances[makerAddress][makerAssetAddress] = erc20Balances[makerAddress][
                         makerAssetAddress
                     ].minus(makerAssetFilledAmount);
-                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][takerAssetAddress].add(
-                        takerAssetFillAmount,
-                    );
+                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][
+                        takerAssetAddress
+                    ].plus(takerAssetFillAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         makerFee,
                     );
-                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][makerAssetAddress].add(
-                        makerAssetFilledAmount,
-                    );
+                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][
+                        makerAssetAddress
+                    ].plus(makerAssetFilledAmount);
                     erc20Balances[takerAddress][takerAssetAddress] = erc20Balances[takerAddress][
                         takerAssetAddress
                     ].minus(takerAssetFillAmount);
@@ -664,7 +664,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(makerFee.add(takerFee));
+                    ].plus(makerFee.plus(takerFee));
                 });
 
                 await exchangeWrapper.batchFillOrdersNoThrowAsync(signedOrders, takerAddress, {
@@ -706,15 +706,15 @@ describe('Exchange wrappers', () => {
                     erc20Balances[makerAddress][makerAssetAddress] = erc20Balances[makerAddress][
                         makerAssetAddress
                     ].minus(makerAssetFilledAmount);
-                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][takerAssetAddress].add(
-                        takerAssetFillAmount,
-                    );
+                    erc20Balances[makerAddress][takerAssetAddress] = erc20Balances[makerAddress][
+                        takerAssetAddress
+                    ].plus(takerAssetFillAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         makerFee,
                     );
-                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][makerAssetAddress].add(
-                        makerAssetFilledAmount,
-                    );
+                    erc20Balances[takerAddress][makerAssetAddress] = erc20Balances[takerAddress][
+                        makerAssetAddress
+                    ].plus(makerAssetFilledAmount);
                     erc20Balances[takerAddress][takerAssetAddress] = erc20Balances[takerAddress][
                         takerAssetAddress
                     ].minus(takerAssetFillAmount);
@@ -723,7 +723,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(makerFee.add(takerFee));
+                    ].plus(makerFee.plus(takerFee));
                 });
 
                 const newOrders = [invalidOrder, ...validOrders];
@@ -773,16 +773,16 @@ describe('Exchange wrappers', () => {
 
                 const newBalances = await erc20Wrapper.getBalancesAsync();
 
-                const makerAssetFilledAmount = signedOrders[0].makerAssetAmount.add(
+                const makerAssetFilledAmount = signedOrders[0].makerAssetAmount.plus(
                     signedOrders[1].makerAssetAmount.dividedToIntegerBy(2),
                 );
-                const makerFee = signedOrders[0].makerFee.add(signedOrders[1].makerFee.dividedToIntegerBy(2));
-                const takerFee = signedOrders[0].takerFee.add(signedOrders[1].takerFee.dividedToIntegerBy(2));
+                const makerFee = signedOrders[0].makerFee.plus(signedOrders[1].makerFee.dividedToIntegerBy(2));
+                const takerFee = signedOrders[0].takerFee.plus(signedOrders[1].takerFee.dividedToIntegerBy(2));
                 expect(newBalances[makerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][defaultMakerAssetAddress].minus(makerAssetFilledAmount),
                 );
                 expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[makerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                    erc20Balances[makerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -791,13 +791,13 @@ describe('Exchange wrappers', () => {
                     erc20Balances[takerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[takerAddress][defaultMakerAssetAddress].add(makerAssetFilledAmount),
+                    erc20Balances[takerAddress][defaultMakerAssetAddress].plus(makerAssetFilledAmount),
                 );
                 expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
                 );
                 expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                    erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                    erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
                 );
             });
 
@@ -809,13 +809,13 @@ describe('Exchange wrappers', () => {
                     ].minus(signedOrder.makerAssetAmount);
                     erc20Balances[makerAddress][defaultTakerAssetAddress] = erc20Balances[makerAddress][
                         defaultTakerAssetAddress
-                    ].add(signedOrder.takerAssetAmount);
+                    ].plus(signedOrder.takerAssetAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         signedOrder.makerFee,
                     );
                     erc20Balances[takerAddress][defaultMakerAssetAddress] = erc20Balances[takerAddress][
                         defaultMakerAssetAddress
-                    ].add(signedOrder.makerAssetAmount);
+                    ].plus(signedOrder.makerAssetAmount);
                     erc20Balances[takerAddress][defaultTakerAssetAddress] = erc20Balances[takerAddress][
                         defaultTakerAssetAddress
                     ].minus(signedOrder.takerAssetAmount);
@@ -824,7 +824,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(signedOrder.makerFee.add(signedOrder.takerFee));
+                    ].plus(signedOrder.makerFee.plus(signedOrder.takerFee));
                 });
                 await exchangeWrapper.marketSellOrdersAsync(signedOrders, takerAddress, {
                     takerAssetFillAmount,
@@ -890,16 +890,16 @@ describe('Exchange wrappers', () => {
 
                 const newBalances = await erc20Wrapper.getBalancesAsync();
 
-                const makerAssetFilledAmount = signedOrders[0].makerAssetAmount.add(
+                const makerAssetFilledAmount = signedOrders[0].makerAssetAmount.plus(
                     signedOrders[1].makerAssetAmount.dividedToIntegerBy(2),
                 );
-                const makerFee = signedOrders[0].makerFee.add(signedOrders[1].makerFee.dividedToIntegerBy(2));
-                const takerFee = signedOrders[0].takerFee.add(signedOrders[1].takerFee.dividedToIntegerBy(2));
+                const makerFee = signedOrders[0].makerFee.plus(signedOrders[1].makerFee.dividedToIntegerBy(2));
+                const takerFee = signedOrders[0].takerFee.plus(signedOrders[1].takerFee.dividedToIntegerBy(2));
                 expect(newBalances[makerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][defaultMakerAssetAddress].minus(makerAssetFilledAmount),
                 );
                 expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[makerAddress][defaultTakerAssetAddress].add(takerAssetFillAmount),
+                    erc20Balances[makerAddress][defaultTakerAssetAddress].plus(takerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -908,13 +908,13 @@ describe('Exchange wrappers', () => {
                     erc20Balances[takerAddress][defaultTakerAssetAddress].minus(takerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[takerAddress][defaultMakerAssetAddress].add(makerAssetFilledAmount),
+                    erc20Balances[takerAddress][defaultMakerAssetAddress].plus(makerAssetFilledAmount),
                 );
                 expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
                 );
                 expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                    erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                    erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
                 );
             });
 
@@ -926,13 +926,13 @@ describe('Exchange wrappers', () => {
                     ].minus(signedOrder.makerAssetAmount);
                     erc20Balances[makerAddress][defaultTakerAssetAddress] = erc20Balances[makerAddress][
                         defaultTakerAssetAddress
-                    ].add(signedOrder.takerAssetAmount);
+                    ].plus(signedOrder.takerAssetAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         signedOrder.makerFee,
                     );
                     erc20Balances[takerAddress][defaultMakerAssetAddress] = erc20Balances[takerAddress][
                         defaultMakerAssetAddress
-                    ].add(signedOrder.makerAssetAmount);
+                    ].plus(signedOrder.makerAssetAmount);
                     erc20Balances[takerAddress][defaultTakerAssetAddress] = erc20Balances[takerAddress][
                         defaultTakerAssetAddress
                     ].minus(signedOrder.takerAssetAmount);
@@ -941,7 +941,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(signedOrder.makerFee.add(signedOrder.takerFee));
+                    ].plus(signedOrder.makerFee.plus(signedOrder.takerFee));
                 });
                 await exchangeWrapper.marketSellOrdersNoThrowAsync(signedOrders, takerAddress, {
                     takerAssetFillAmount,
@@ -971,13 +971,13 @@ describe('Exchange wrappers', () => {
                     ].minus(signedOrder.makerAssetAmount);
                     erc20Balances[makerAddress][defaultTakerAssetAddress] = erc20Balances[makerAddress][
                         defaultTakerAssetAddress
-                    ].add(signedOrder.takerAssetAmount);
+                    ].plus(signedOrder.takerAssetAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         signedOrder.makerFee,
                     );
                     erc20Balances[takerAddress][defaultMakerAssetAddress] = erc20Balances[takerAddress][
                         defaultMakerAssetAddress
-                    ].add(signedOrder.makerAssetAmount);
+                    ].plus(signedOrder.makerAssetAmount);
                     erc20Balances[takerAddress][defaultTakerAssetAddress] = erc20Balances[takerAddress][
                         defaultTakerAssetAddress
                     ].minus(signedOrder.takerAssetAmount);
@@ -986,7 +986,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(signedOrder.makerFee.add(signedOrder.takerFee));
+                    ].plus(signedOrder.makerFee.plus(signedOrder.takerFee));
                 });
                 await exchangeWrapper.marketSellOrdersNoThrowAsync(signedOrders, takerAddress, {
                     takerAssetFillAmount,
@@ -1034,16 +1034,16 @@ describe('Exchange wrappers', () => {
 
                 const newBalances = await erc20Wrapper.getBalancesAsync();
 
-                const makerAmountBought = signedOrders[0].takerAssetAmount.add(
+                const makerAmountBought = signedOrders[0].takerAssetAmount.plus(
                     signedOrders[1].takerAssetAmount.dividedToIntegerBy(2),
                 );
-                const makerFee = signedOrders[0].makerFee.add(signedOrders[1].makerFee.dividedToIntegerBy(2));
-                const takerFee = signedOrders[0].takerFee.add(signedOrders[1].takerFee.dividedToIntegerBy(2));
+                const makerFee = signedOrders[0].makerFee.plus(signedOrders[1].makerFee.dividedToIntegerBy(2));
+                const takerFee = signedOrders[0].takerFee.plus(signedOrders[1].takerFee.dividedToIntegerBy(2));
                 expect(newBalances[makerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[makerAddress][defaultTakerAssetAddress].add(makerAmountBought),
+                    erc20Balances[makerAddress][defaultTakerAssetAddress].plus(makerAmountBought),
                 );
                 expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -1052,13 +1052,13 @@ describe('Exchange wrappers', () => {
                     erc20Balances[takerAddress][defaultTakerAssetAddress].minus(makerAmountBought),
                 );
                 expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[takerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount),
+                    erc20Balances[takerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
                 );
                 expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                    erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                    erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
                 );
             });
 
@@ -1070,13 +1070,13 @@ describe('Exchange wrappers', () => {
                     ].minus(signedOrder.makerAssetAmount);
                     erc20Balances[makerAddress][defaultTakerAssetAddress] = erc20Balances[makerAddress][
                         defaultTakerAssetAddress
-                    ].add(signedOrder.takerAssetAmount);
+                    ].plus(signedOrder.takerAssetAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         signedOrder.makerFee,
                     );
                     erc20Balances[takerAddress][defaultMakerAssetAddress] = erc20Balances[takerAddress][
                         defaultMakerAssetAddress
-                    ].add(signedOrder.makerAssetAmount);
+                    ].plus(signedOrder.makerAssetAmount);
                     erc20Balances[takerAddress][defaultTakerAssetAddress] = erc20Balances[takerAddress][
                         defaultTakerAssetAddress
                     ].minus(signedOrder.takerAssetAmount);
@@ -1085,7 +1085,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(signedOrder.makerFee.add(signedOrder.takerFee));
+                    ].plus(signedOrder.makerFee.plus(signedOrder.takerFee));
                 });
                 await exchangeWrapper.marketBuyOrdersAsync(signedOrders, takerAddress, {
                     makerAssetFillAmount,
@@ -1149,16 +1149,16 @@ describe('Exchange wrappers', () => {
 
                 const newBalances = await erc20Wrapper.getBalancesAsync();
 
-                const makerAmountBought = signedOrders[0].takerAssetAmount.add(
+                const makerAmountBought = signedOrders[0].takerAssetAmount.plus(
                     signedOrders[1].takerAssetAmount.dividedToIntegerBy(2),
                 );
-                const makerFee = signedOrders[0].makerFee.add(signedOrders[1].makerFee.dividedToIntegerBy(2));
-                const takerFee = signedOrders[0].takerFee.add(signedOrders[1].takerFee.dividedToIntegerBy(2));
+                const makerFee = signedOrders[0].makerFee.plus(signedOrders[1].makerFee.dividedToIntegerBy(2));
+                const takerFee = signedOrders[0].takerFee.plus(signedOrders[1].takerFee.dividedToIntegerBy(2));
                 expect(newBalances[makerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][defaultMakerAssetAddress].minus(makerAssetFillAmount),
                 );
                 expect(newBalances[makerAddress][defaultTakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[makerAddress][defaultTakerAssetAddress].add(makerAmountBought),
+                    erc20Balances[makerAddress][defaultTakerAssetAddress].plus(makerAmountBought),
                 );
                 expect(newBalances[makerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[makerAddress][zrxToken.address].minus(makerFee),
@@ -1167,13 +1167,13 @@ describe('Exchange wrappers', () => {
                     erc20Balances[takerAddress][defaultTakerAssetAddress].minus(makerAmountBought),
                 );
                 expect(newBalances[takerAddress][defaultMakerAssetAddress]).to.be.bignumber.equal(
-                    erc20Balances[takerAddress][defaultMakerAssetAddress].add(makerAssetFillAmount),
+                    erc20Balances[takerAddress][defaultMakerAssetAddress].plus(makerAssetFillAmount),
                 );
                 expect(newBalances[takerAddress][zrxToken.address]).to.be.bignumber.equal(
                     erc20Balances[takerAddress][zrxToken.address].minus(takerFee),
                 );
                 expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
-                    erc20Balances[feeRecipientAddress][zrxToken.address].add(makerFee.add(takerFee)),
+                    erc20Balances[feeRecipientAddress][zrxToken.address].plus(makerFee.plus(takerFee)),
                 );
             });
 
@@ -1185,13 +1185,13 @@ describe('Exchange wrappers', () => {
                     ].minus(signedOrder.makerAssetAmount);
                     erc20Balances[makerAddress][defaultTakerAssetAddress] = erc20Balances[makerAddress][
                         defaultTakerAssetAddress
-                    ].add(signedOrder.takerAssetAmount);
+                    ].plus(signedOrder.takerAssetAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         signedOrder.makerFee,
                     );
                     erc20Balances[takerAddress][defaultMakerAssetAddress] = erc20Balances[takerAddress][
                         defaultMakerAssetAddress
-                    ].add(signedOrder.makerAssetAmount);
+                    ].plus(signedOrder.makerAssetAmount);
                     erc20Balances[takerAddress][defaultTakerAssetAddress] = erc20Balances[takerAddress][
                         defaultTakerAssetAddress
                     ].minus(signedOrder.takerAssetAmount);
@@ -1200,7 +1200,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(signedOrder.makerFee.add(signedOrder.takerFee));
+                    ].plus(signedOrder.makerFee.plus(signedOrder.takerFee));
                 });
                 await exchangeWrapper.marketBuyOrdersNoThrowAsync(signedOrders, takerAddress, {
                     makerAssetFillAmount,
@@ -1231,13 +1231,13 @@ describe('Exchange wrappers', () => {
                     ].minus(signedOrder.makerAssetAmount);
                     erc20Balances[makerAddress][defaultTakerAssetAddress] = erc20Balances[makerAddress][
                         defaultTakerAssetAddress
-                    ].add(signedOrder.takerAssetAmount);
+                    ].plus(signedOrder.takerAssetAmount);
                     erc20Balances[makerAddress][zrxToken.address] = erc20Balances[makerAddress][zrxToken.address].minus(
                         signedOrder.makerFee,
                     );
                     erc20Balances[takerAddress][defaultMakerAssetAddress] = erc20Balances[takerAddress][
                         defaultMakerAssetAddress
-                    ].add(signedOrder.makerAssetAmount);
+                    ].plus(signedOrder.makerAssetAmount);
                     erc20Balances[takerAddress][defaultTakerAssetAddress] = erc20Balances[takerAddress][
                         defaultTakerAssetAddress
                     ].minus(signedOrder.takerAssetAmount);
@@ -1246,7 +1246,7 @@ describe('Exchange wrappers', () => {
                     );
                     erc20Balances[feeRecipientAddress][zrxToken.address] = erc20Balances[feeRecipientAddress][
                         zrxToken.address
-                    ].add(signedOrder.makerFee.add(signedOrder.takerFee));
+                    ].plus(signedOrder.makerFee.plus(signedOrder.takerFee));
                 });
                 await exchangeWrapper.marketBuyOrdersNoThrowAsync(signedOrders, takerAddress, {
                     makerAssetFillAmount,
diff --git a/contracts/protocol/test/utils/fill_order_combinatorial_utils.ts b/contracts/protocol/test/utils/fill_order_combinatorial_utils.ts
index 2fd33bebd..c2f530e5b 100644
--- a/contracts/protocol/test/utils/fill_order_combinatorial_utils.ts
+++ b/contracts/protocol/test/utils/fill_order_combinatorial_utils.ts
@@ -469,7 +469,7 @@ export class FillOrderCombinatorialUtils {
         const remainingTakerAmountToFill = signedOrder.takerAssetAmount.minus(alreadyFilledTakerAmount);
         const expFilledTakerAmount = takerAssetFillAmount.gt(remainingTakerAmountToFill)
             ? remainingTakerAmountToFill
-            : alreadyFilledTakerAmount.add(takerAssetFillAmount);
+            : alreadyFilledTakerAmount.plus(takerAssetFillAmount);
 
         const expFilledMakerAmount = orderUtils.getPartialAmountFloor(
             expFilledTakerAmount,
@@ -644,7 +644,7 @@ export class FillOrderCombinatorialUtils {
                 break;
 
             case TakerAssetFillAmountScenario.GreaterThanRemainingFillableTakerAssetAmount:
-                takerAssetFillAmount = fillableTakerAssetAmount.add(1);
+                takerAssetFillAmount = fillableTakerAssetAmount.plus(1);
                 break;
 
             case TakerAssetFillAmountScenario.LessThanRemainingFillableTakerAssetAmount:
@@ -657,7 +657,7 @@ export class FillOrderCombinatorialUtils {
                         'Cannot test `TakerAssetFillAmountScenario.LessThanRemainingFillableTakerAssetAmount` together with ERC721 assets since orders involving ERC721 must always be filled exactly.',
                     );
                 }
-                takerAssetFillAmount = fillableTakerAssetAmount.div(2).floor();
+                takerAssetFillAmount = fillableTakerAssetAmount.div(2).integerValue(BigNumber.ROUND_FLOOR);
                 break;
 
             default:
diff --git a/contracts/protocol/test/utils/match_order_tester.ts b/contracts/protocol/test/utils/match_order_tester.ts
index 31864820f..0ba8017c5 100644
--- a/contracts/protocol/test/utils/match_order_tester.ts
+++ b/contracts/protocol/test/utils/match_order_tester.ts
@@ -66,7 +66,7 @@ export class MatchOrderTester {
         const feePaidByRightMaker = new BigNumber(rightLog.makerFeePaid);
         const feePaidByTakerRight = new BigNumber(rightLog.takerFeePaid);
         // Derive amount received by taker
-        const amountReceivedByTaker = amountSoldByLeftMaker.sub(amountBoughtByRightMaker);
+        const amountReceivedByTaker = amountSoldByLeftMaker.minus(amountBoughtByRightMaker);
         // Assert log values - left order
         expect(amountBoughtByLeftMaker, 'Checking logged amount bought by left maker').to.be.bignumber.equal(
             expectedTransferAmounts.amountBoughtByLeftMaker,
@@ -267,14 +267,16 @@ export class MatchOrderTester {
         // Assert left order status
         const maxAmountBoughtByLeftMaker = signedOrderLeft.takerAssetAmount.minus(initialLeftOrderFilledAmount);
         const leftOrderInfo: OrderInfo = await this._exchangeWrapper.getOrderInfoAsync(signedOrderLeft);
-        const leftExpectedStatus = expectedTransferAmounts.amountBoughtByLeftMaker.equals(maxAmountBoughtByLeftMaker)
+        const leftExpectedStatus = expectedTransferAmounts.amountBoughtByLeftMaker.isEqualTo(maxAmountBoughtByLeftMaker)
             ? OrderStatus.FullyFilled
             : OrderStatus.Fillable;
         expect(leftOrderInfo.orderStatus, 'Checking exchange status for left order').to.be.equal(leftExpectedStatus);
         // Assert right order status
         const maxAmountBoughtByRightMaker = signedOrderRight.takerAssetAmount.minus(initialRightOrderFilledAmount);
         const rightOrderInfo: OrderInfo = await this._exchangeWrapper.getOrderInfoAsync(signedOrderRight);
-        const rightExpectedStatus = expectedTransferAmounts.amountBoughtByRightMaker.equals(maxAmountBoughtByRightMaker)
+        const rightExpectedStatus = expectedTransferAmounts.amountBoughtByRightMaker.isEqualTo(
+            maxAmountBoughtByRightMaker,
+        )
             ? OrderStatus.FullyFilled
             : OrderStatus.Fillable;
         expect(rightOrderInfo.orderStatus, 'Checking exchange status for right order').to.be.equal(rightExpectedStatus);
@@ -364,13 +366,13 @@ export class MatchOrderTester {
             // Right Maker
             expectedNewERC20BalancesByOwner[makerAddressRight][
                 takerAssetAddressRight
-            ] = expectedNewERC20BalancesByOwner[makerAddressRight][takerAssetAddressRight].add(
+            ] = expectedNewERC20BalancesByOwner[makerAddressRight][takerAssetAddressRight].plus(
                 expectedTransferAmounts.amountBoughtByRightMaker,
             );
             // Taker
             expectedNewERC20BalancesByOwner[takerAddress][makerAssetAddressLeft] = expectedNewERC20BalancesByOwner[
                 takerAddress
-            ][makerAssetAddressLeft].add(expectedTransferAmounts.amountReceivedByTaker);
+            ][makerAssetAddressLeft].plus(expectedTransferAmounts.amountReceivedByTaker);
         } else if (makerAssetProxyIdLeft === AssetProxyId.ERC721) {
             // Decode asset data
             const erc721AssetData = assetDataUtils.decodeERC721AssetData(signedOrderLeft.makerAssetData);
@@ -395,7 +397,7 @@ export class MatchOrderTester {
             // Left Maker
             expectedNewERC20BalancesByOwner[makerAddressLeft][takerAssetAddressLeft] = expectedNewERC20BalancesByOwner[
                 makerAddressLeft
-            ][takerAssetAddressLeft].add(expectedTransferAmounts.amountBoughtByLeftMaker);
+            ][takerAssetAddressLeft].plus(expectedTransferAmounts.amountBoughtByLeftMaker);
             // Right Maker
             expectedNewERC20BalancesByOwner[makerAddressRight][
                 makerAssetAddressRight
@@ -426,19 +428,19 @@ export class MatchOrderTester {
         expectedNewERC20BalancesByOwner[takerAddress][this._feeTokenAddress] = expectedNewERC20BalancesByOwner[
             takerAddress
         ][this._feeTokenAddress].minus(
-            expectedTransferAmounts.feePaidByTakerLeft.add(expectedTransferAmounts.feePaidByTakerRight),
+            expectedTransferAmounts.feePaidByTakerLeft.plus(expectedTransferAmounts.feePaidByTakerRight),
         );
         // Left Fee Recipient Fees
         expectedNewERC20BalancesByOwner[feeRecipientAddressLeft][
             this._feeTokenAddress
-        ] = expectedNewERC20BalancesByOwner[feeRecipientAddressLeft][this._feeTokenAddress].add(
-            expectedTransferAmounts.feePaidByLeftMaker.add(expectedTransferAmounts.feePaidByTakerLeft),
+        ] = expectedNewERC20BalancesByOwner[feeRecipientAddressLeft][this._feeTokenAddress].plus(
+            expectedTransferAmounts.feePaidByLeftMaker.plus(expectedTransferAmounts.feePaidByTakerLeft),
         );
         // Right Fee Recipient Fees
         expectedNewERC20BalancesByOwner[feeRecipientAddressRight][
             this._feeTokenAddress
-        ] = expectedNewERC20BalancesByOwner[feeRecipientAddressRight][this._feeTokenAddress].add(
-            expectedTransferAmounts.feePaidByRightMaker.add(expectedTransferAmounts.feePaidByTakerRight),
+        ] = expectedNewERC20BalancesByOwner[feeRecipientAddressRight][this._feeTokenAddress].plus(
+            expectedTransferAmounts.feePaidByRightMaker.plus(expectedTransferAmounts.feePaidByTakerRight),
         );
 
         return [expectedNewERC20BalancesByOwner, expectedNewERC721TokenIdsByOwner];
diff --git a/contracts/test-utils/CHANGELOG.json b/contracts/test-utils/CHANGELOG.json
index 91485313a..ae1575e43 100644
--- a/contracts/test-utils/CHANGELOG.json
+++ b/contracts/test-utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "2.0.1",
         "changes": [
diff --git a/contracts/test-utils/package.json b/contracts/test-utils/package.json
index b7cfcb5b6..b0f4713af 100644
--- a/contracts/test-utils/package.json
+++ b/contracts/test-utils/package.json
@@ -61,7 +61,7 @@
         "bn.js": "^4.11.8",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereum-types": "^1.1.6",
         "ethereumjs-abi": "0.6.5",
diff --git a/contracts/test-utils/src/order_factory.ts b/contracts/test-utils/src/order_factory.ts
index 2449d1a8a..b0f435ff2 100644
--- a/contracts/test-utils/src/order_factory.ts
+++ b/contracts/test-utils/src/order_factory.ts
@@ -21,7 +21,7 @@ export class OrderFactory {
         const currentBlockTimestamp = await getLatestBlockTimestampAsync();
         const order = ({
             senderAddress: constants.NULL_ADDRESS,
-            expirationTimeSeconds: new BigNumber(currentBlockTimestamp).add(tenMinutesInSeconds),
+            expirationTimeSeconds: new BigNumber(currentBlockTimestamp).plus(tenMinutesInSeconds),
             salt: generatePseudoRandomSalt(),
             takerAddress: constants.NULL_ADDRESS,
             ...this._defaultOrderParams,
diff --git a/contracts/test-utils/src/order_utils.ts b/contracts/test-utils/src/order_utils.ts
index 4f7a34011..fd336bb47 100644
--- a/contracts/test-utils/src/order_utils.ts
+++ b/contracts/test-utils/src/order_utils.ts
@@ -7,9 +7,9 @@ import { CancelOrder, MatchOrder } from './types';
 export const orderUtils = {
     getPartialAmountFloor(numerator: BigNumber, denominator: BigNumber, target: BigNumber): BigNumber {
         const partialAmount = numerator
-            .mul(target)
+            .multipliedBy(target)
             .div(denominator)
-            .floor();
+            .integerValue(BigNumber.ROUND_FLOOR);
         return partialAmount;
     },
     createFill: (signedOrder: SignedOrder, takerAssetFillAmount?: BigNumber) => {
diff --git a/contracts/tokens/CHANGELOG.json b/contracts/tokens/CHANGELOG.json
index 6adebc471..724ab1e4a 100644
--- a/contracts/tokens/CHANGELOG.json
+++ b/contracts/tokens/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.6",
         "changes": [
diff --git a/contracts/tokens/package.json b/contracts/tokens/package.json
index ce680ab09..bd0316919 100644
--- a/contracts/tokens/package.json
+++ b/contracts/tokens/package.json
@@ -56,7 +56,7 @@
         "@types/yargs": "^10.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereumjs-abi": "0.6.5",
         "make-promises-safe": "^1.1.0",
diff --git a/contracts/tokens/test/unlimited_allowance_token.ts b/contracts/tokens/test/unlimited_allowance_token.ts
index 6d5a29b23..f0b8e53a4 100644
--- a/contracts/tokens/test/unlimited_allowance_token.ts
+++ b/contracts/tokens/test/unlimited_allowance_token.ts
@@ -109,7 +109,7 @@ describe('UnlimitedAllowanceToken', () => {
             const amountToTransfer = ownerBalance;
 
             const spenderAllowance = await token.allowance.callAsync(owner, spender);
-            const isSpenderAllowanceInsufficient = spenderAllowance.cmp(amountToTransfer) < 0;
+            const isSpenderAllowanceInsufficient = spenderAllowance.comparedTo(amountToTransfer) < 0;
             expect(isSpenderAllowanceInsufficient).to.be.true();
 
             return expectContractCallFailedAsync(
diff --git a/contracts/tokens/test/zrx_token.ts b/contracts/tokens/test/zrx_token.ts
index 5dc8447f6..820b054e6 100644
--- a/contracts/tokens/test/zrx_token.ts
+++ b/contracts/tokens/test/zrx_token.ts
@@ -117,7 +117,7 @@ describe('ZRXToken', () => {
             const amountToTransfer = ownerBalance;
 
             const spenderAllowance = await zrxToken.allowance.callAsync(owner, spender);
-            const isSpenderAllowanceInsufficient = spenderAllowance.cmp(amountToTransfer) < 0;
+            const isSpenderAllowanceInsufficient = spenderAllowance.comparedTo(amountToTransfer) < 0;
             expect(isSpenderAllowanceInsufficient).to.be.true();
 
             const didReturnTrue = await zrxToken.transferFrom.callAsync(owner, spender, amountToTransfer, {
diff --git a/contracts/utils/CHANGELOG.json b/contracts/utils/CHANGELOG.json
index 6adebc471..724ab1e4a 100644
--- a/contracts/utils/CHANGELOG.json
+++ b/contracts/utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.6",
         "changes": [
diff --git a/contracts/utils/package.json b/contracts/utils/package.json
index a6d38d0d8..4e45169fd 100644
--- a/contracts/utils/package.json
+++ b/contracts/utils/package.json
@@ -57,7 +57,7 @@
         "bn.js": "^4.11.8",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ethereumjs-abi": "0.6.5",
         "make-promises-safe": "^1.1.0",
diff --git a/packages/0x.js/CHANGELOG.json b/packages/0x.js/CHANGELOG.json
index 276bdd479..20778f8bb 100644
--- a/packages/0x.js/CHANGELOG.json
+++ b/packages/0x.js/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "3.0.3",
         "changes": [
diff --git a/packages/0x.js/package.json b/packages/0x.js/package.json
index f4f1c82e0..64054d288 100644
--- a/packages/0x.js/package.json
+++ b/packages/0x.js/package.json
@@ -54,7 +54,7 @@
         "awesome-typescript-loader": "^5.2.1",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "copyfiles": "^2.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
diff --git a/packages/abi-gen-templates/CHANGELOG.json b/packages/abi-gen-templates/CHANGELOG.json
index b825c4f1f..7d444d0ca 100644
--- a/packages/abi-gen-templates/CHANGELOG.json
+++ b/packages/abi-gen-templates/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.2",
         "changes": [
diff --git a/packages/abi-gen-wrappers/CHANGELOG.json b/packages/abi-gen-wrappers/CHANGELOG.json
index 381b37cda..c604302b5 100644
--- a/packages/abi-gen-wrappers/CHANGELOG.json
+++ b/packages/abi-gen-wrappers/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "version": "2.2.0",
         "changes": [
             {
diff --git a/packages/abi-gen/CHANGELOG.json b/packages/abi-gen/CHANGELOG.json
index ab516e4c6..173617b65 100644
--- a/packages/abi-gen/CHANGELOG.json
+++ b/packages/abi-gen/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.22",
         "changes": [
diff --git a/packages/assert/CHANGELOG.json b/packages/assert/CHANGELOG.json
index 0210f9400..278b7dfa1 100644
--- a/packages/assert/CHANGELOG.json
+++ b/packages/assert/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.23",
         "changes": [
diff --git a/packages/assert/src/index.ts b/packages/assert/src/index.ts
index 2d28d51e1..741bd78e1 100644
--- a/packages/assert/src/index.ts
+++ b/packages/assert/src/index.ts
@@ -7,12 +7,12 @@ const HEX_REGEX = /^0x[0-9A-F]*$/i;
 
 export const assert = {
     isBigNumber(variableName: string, value: BigNumber): void {
-        const isBigNumber = _.isObject(value) && (value as any).isBigNumber;
+        const isBigNumber = BigNumber.isBigNumber(value);
         assert.assert(isBigNumber, assert.typeAssertionMessage(variableName, 'BigNumber', value));
     },
     isValidBaseUnitAmount(variableName: string, value: BigNumber): void {
         assert.isBigNumber(variableName, value);
-        const isNegative = value.lessThan(0);
+        const isNegative = value.isLessThan(0);
         assert.assert(!isNegative, `${variableName} cannot be a negative number, found value: ${value.toNumber()}`);
         const hasDecimals = value.decimalPlaces() !== 0;
         assert.assert(
diff --git a/packages/asset-buyer/CHANGELOG.json b/packages/asset-buyer/CHANGELOG.json
index 3bb95fdba..2de603de0 100644
--- a/packages/asset-buyer/CHANGELOG.json
+++ b/packages/asset-buyer/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "5.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "version": "4.1.0",
         "changes": [
             {
diff --git a/packages/asset-buyer/package.json b/packages/asset-buyer/package.json
index 454e9cc1c..0f79ac06a 100644
--- a/packages/asset-buyer/package.json
+++ b/packages/asset-buyer/package.json
@@ -56,7 +56,7 @@
         "@types/node": "*",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^4.1.0",
diff --git a/packages/asset-buyer/src/utils/buy_quote_calculator.ts b/packages/asset-buyer/src/utils/buy_quote_calculator.ts
index fcded6ab1..125841094 100644
--- a/packages/asset-buyer/src/utils/buy_quote_calculator.ts
+++ b/packages/asset-buyer/src/utils/buy_quote_calculator.ts
@@ -22,7 +22,7 @@ export const buyQuoteCalculator = {
         const remainingFillableMakerAssetAmounts = ordersAndFillableAmounts.remainingFillableMakerAssetAmounts;
         const feeOrders = feeOrdersAndFillableAmounts.orders;
         const remainingFillableFeeAmounts = feeOrdersAndFillableAmounts.remainingFillableMakerAssetAmounts;
-        const slippageBufferAmount = assetBuyAmount.mul(slippagePercentage).round();
+        const slippageBufferAmount = assetBuyAmount.multipliedBy(slippagePercentage).integerValue();
         // find the orders that cover the desired assetBuyAmount (with slippage)
         const {
             resultOrders,
@@ -43,7 +43,9 @@ export const buyQuoteCalculator = {
             const multiplierNeededWithSlippage = new BigNumber(1).plus(slippagePercentage);
             // Given amountAvailableToFillConsideringSlippage * multiplierNeededWithSlippage = amountAbleToFill
             // We divide amountUnableToFill by multiplierNeededWithSlippage to determine amountAvailableToFillConsideringSlippage
-            const amountAvailableToFillConsideringSlippage = amountAbleToFill.div(multiplierNeededWithSlippage).floor();
+            const amountAvailableToFillConsideringSlippage = amountAbleToFill
+                .div(multiplierNeededWithSlippage)
+                .integerValue(BigNumber.ROUND_FLOOR);
 
             throw new InsufficientAssetLiquidityError(amountAvailableToFillConsideringSlippage);
         }
@@ -131,7 +133,7 @@ function calculateQuoteInfo(
         zrxEthAmount = findEthAmountNeededToBuyZrx(feeOrdersAndFillableAmounts, zrxAmountToBuyAsset);
     }
     // eth amount needed to buy the affiliate fee
-    const affiliateFeeEthAmount = assetEthAmount.mul(feePercentage).ceil();
+    const affiliateFeeEthAmount = assetEthAmount.multipliedBy(feePercentage).integerValue(BigNumber.ROUND_CEIL);
     // eth amount needed for fees is the sum of affiliate fee and zrx fee
     const feeEthAmount = affiliateFeeEthAmount.plus(zrxEthAmount);
     // eth amount needed in total is the sum of the amount needed for the asset and the amount needed for fees
@@ -168,9 +170,9 @@ function findEthAmountNeededToBuyZrx(
                 order,
                 makerFillAmount,
             );
-            const extraFeeAmount = remainingFillableMakerAssetAmount.greaterThanOrEqualTo(adjustedMakerFillAmount)
+            const extraFeeAmount = remainingFillableMakerAssetAmount.isGreaterThanOrEqualTo(adjustedMakerFillAmount)
                 ? constants.ZERO_AMOUNT
-                : adjustedMakerFillAmount.sub(makerFillAmount);
+                : adjustedMakerFillAmount.minus(makerFillAmount);
             return {
                 totalEthAmount: totalEthAmount.plus(takerFillAmount),
                 remainingZrxBuyAmount: BigNumber.max(
diff --git a/packages/asset-buyer/src/utils/order_provider_response_processor.ts b/packages/asset-buyer/src/utils/order_provider_response_processor.ts
index 4244d196c..f08cd6150 100644
--- a/packages/asset-buyer/src/utils/order_provider_response_processor.ts
+++ b/packages/asset-buyer/src/utils/order_provider_response_processor.ts
@@ -109,11 +109,8 @@ function getValidOrdersWithRemainingFillableMakerAssetAmountsFromOnChain(
                 return accOrders;
             }
             // if the order IS fillable, add the order and calculate the remaining fillable amount
-            const transferrableAssetAmount = BigNumber.min([traderInfo.makerAllowance, traderInfo.makerBalance]);
-            const transferrableFeeAssetAmount = BigNumber.min([
-                traderInfo.makerZrxAllowance,
-                traderInfo.makerZrxBalance,
-            ]);
+            const transferrableAssetAmount = BigNumber.min(traderInfo.makerAllowance, traderInfo.makerBalance);
+            const transferrableFeeAssetAmount = BigNumber.min(traderInfo.makerZrxAllowance, traderInfo.makerZrxBalance);
             const remainingTakerAssetAmount = order.takerAssetAmount.minus(orderInfo.orderTakerAssetFilledAmount);
             const remainingMakerAssetAmount = orderUtils.getRemainingMakerAmount(order, remainingTakerAssetAmount);
             const remainingFillableCalculator = new RemainingFillableCalculator(
diff --git a/packages/asset-buyer/src/utils/order_utils.ts b/packages/asset-buyer/src/utils/order_utils.ts
index 1cc2cf95f..3ea3cafd3 100644
--- a/packages/asset-buyer/src/utils/order_utils.ts
+++ b/packages/asset-buyer/src/utils/order_utils.ts
@@ -9,8 +9,8 @@ export const orderUtils = {
     },
     willOrderExpire(order: SignedOrder, secondsFromNow: number): boolean {
         const millisecondsInSecond = 1000;
-        const currentUnixTimestampSec = new BigNumber(Date.now() / millisecondsInSecond).round();
-        return order.expirationTimeSeconds.lessThan(currentUnixTimestampSec.plus(secondsFromNow));
+        const currentUnixTimestampSec = new BigNumber(Date.now() / millisecondsInSecond).integerValue();
+        return order.expirationTimeSeconds.isLessThan(currentUnixTimestampSec.plus(secondsFromNow));
     },
     isOpenOrder(order: SignedOrder): boolean {
         return order.takerAddress === constants.NULL_ADDRESS;
@@ -20,43 +20,43 @@ export const orderUtils = {
         const remainingMakerAmount = remainingTakerAmount
             .times(order.makerAssetAmount)
             .div(order.takerAssetAmount)
-            .floor();
+            .integerValue(BigNumber.ROUND_FLOOR);
         return remainingMakerAmount;
     },
     // given a desired amount of makerAsset, calculate how much takerAsset is required to fill that amount
     getTakerFillAmount(order: SignedOrder, makerFillAmount: BigNumber): BigNumber {
         // Round up because exchange rate favors Maker
         const takerFillAmount = makerFillAmount
-            .mul(order.takerAssetAmount)
+            .multipliedBy(order.takerAssetAmount)
             .div(order.makerAssetAmount)
-            .ceil();
+            .integerValue(BigNumber.ROUND_CEIL);
         return takerFillAmount;
     },
     // given a desired amount of takerAsset to fill, calculate how much fee is required by the taker to fill that amount
     getTakerFeeAmount(order: SignedOrder, takerFillAmount: BigNumber): BigNumber {
         // Round down because Taker fee rate favors Taker
         const takerFeeAmount = takerFillAmount
-            .mul(order.takerFee)
+            .multipliedBy(order.takerFee)
             .div(order.takerAssetAmount)
-            .floor();
+            .integerValue(BigNumber.ROUND_FLOOR);
         return takerFeeAmount;
     },
     // given a desired amount of takerAsset to fill, calculate how much makerAsset will be filled
     getMakerFillAmount(order: SignedOrder, takerFillAmount: BigNumber): BigNumber {
         // Round down because exchange rate favors Maker
         const makerFillAmount = takerFillAmount
-            .mul(order.makerAssetAmount)
+            .multipliedBy(order.makerAssetAmount)
             .div(order.takerAssetAmount)
-            .floor();
+            .integerValue(BigNumber.ROUND_FLOOR);
         return makerFillAmount;
     },
     // given a desired amount of makerAsset, calculate how much fee is required by the maker to fill that amount
     getMakerFeeAmount(order: SignedOrder, makerFillAmount: BigNumber): BigNumber {
         // Round down because Maker fee rate favors Maker
         const makerFeeAmount = makerFillAmount
-            .mul(order.makerFee)
+            .multipliedBy(order.makerFee)
             .div(order.makerAssetAmount)
-            .floor();
+            .integerValue(BigNumber.ROUND_FLOOR);
         return makerFeeAmount;
     },
     // given a desired amount of ZRX from a fee order, calculate how much takerAsset is required to fill that amount
@@ -64,9 +64,9 @@ export const orderUtils = {
     getTakerFillAmountForFeeOrder(order: SignedOrder, makerFillAmount: BigNumber): [BigNumber, BigNumber] {
         // For each unit of TakerAsset we buy (MakerAsset - TakerFee)
         const adjustedTakerFillAmount = makerFillAmount
-            .mul(order.takerAssetAmount)
-            .div(order.makerAssetAmount.sub(order.takerFee))
-            .ceil();
+            .multipliedBy(order.takerAssetAmount)
+            .div(order.makerAssetAmount.minus(order.takerFee))
+            .integerValue(BigNumber.ROUND_CEIL);
         // The amount that we buy will be greater than makerFillAmount, since we buy some amount for fees.
         const adjustedMakerFillAmount = orderUtils.getMakerFillAmount(order, adjustedTakerFillAmount);
         return [adjustedTakerFillAmount, adjustedMakerFillAmount];
diff --git a/packages/asset-buyer/test/buy_quote_calculator_test.ts b/packages/asset-buyer/test/buy_quote_calculator_test.ts
index 880f55180..177fd8fe6 100644
--- a/packages/asset-buyer/test/buy_quote_calculator_test.ts
+++ b/packages/asset-buyer/test/buy_quote_calculator_test.ts
@@ -234,7 +234,7 @@ describe('buyQuoteCalculator', () => {
             const expectedEthAmountForAsset = new BigNumber(50);
             const expectedEthAmountForZrxFees = new BigNumber(100);
             const expectedFillEthAmount = expectedEthAmountForAsset;
-            const expectedAffiliateFeeEthAmount = expectedEthAmountForAsset.mul(feePercentage);
+            const expectedAffiliateFeeEthAmount = expectedEthAmountForAsset.multipliedBy(feePercentage);
             const expectedFeeEthAmount = expectedAffiliateFeeEthAmount.plus(expectedEthAmountForZrxFees);
             const expectedTotalEthAmount = expectedFillEthAmount.plus(expectedFeeEthAmount);
             expect(buyQuote.bestCaseQuoteInfo.assetEthAmount).to.bignumber.equal(expectedFillEthAmount);
@@ -272,7 +272,7 @@ describe('buyQuoteCalculator', () => {
             const expectedEthAmountForAsset = new BigNumber(50);
             const expectedEthAmountForZrxFees = new BigNumber(100);
             const expectedFillEthAmount = expectedEthAmountForAsset;
-            const expectedAffiliateFeeEthAmount = expectedEthAmountForAsset.mul(feePercentage);
+            const expectedAffiliateFeeEthAmount = expectedEthAmountForAsset.multipliedBy(feePercentage);
             const expectedFeeEthAmount = expectedAffiliateFeeEthAmount.plus(expectedEthAmountForZrxFees);
             const expectedTotalEthAmount = expectedFillEthAmount.plus(expectedFeeEthAmount);
             expect(buyQuote.bestCaseQuoteInfo.assetEthAmount).to.bignumber.equal(expectedFillEthAmount);
@@ -282,7 +282,7 @@ describe('buyQuoteCalculator', () => {
             const expectedWorstEthAmountForAsset = new BigNumber(100);
             const expectedWorstEthAmountForZrxFees = new BigNumber(208);
             const expectedWorstFillEthAmount = expectedWorstEthAmountForAsset;
-            const expectedWorstAffiliateFeeEthAmount = expectedWorstEthAmountForAsset.mul(feePercentage);
+            const expectedWorstAffiliateFeeEthAmount = expectedWorstEthAmountForAsset.multipliedBy(feePercentage);
             const expectedWorstFeeEthAmount = expectedWorstAffiliateFeeEthAmount.plus(expectedWorstEthAmountForZrxFees);
             const expectedWorstTotalEthAmount = expectedWorstFillEthAmount.plus(expectedWorstFeeEthAmount);
             expect(buyQuote.worstCaseQuoteInfo.assetEthAmount).to.bignumber.equal(expectedWorstFillEthAmount);
diff --git a/packages/base-contract/CHANGELOG.json b/packages/base-contract/CHANGELOG.json
index 68ebe8d9e..63b1fe8f7 100644
--- a/packages/base-contract/CHANGELOG.json
+++ b/packages/base-contract/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "3.0.13",
         "changes": [
diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
index c2b7b943b..0238106f3 100644
--- a/packages/base-contract/src/index.ts
+++ b/packages/base-contract/src/index.ts
@@ -1,4 +1,4 @@
-import { AbiEncoder, abiUtils } from '@0x/utils';
+import { AbiEncoder, abiUtils, BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import {
     AbiDefinition,
@@ -43,7 +43,7 @@ export class BaseContract {
         return type === 'address' ? value.toLowerCase() : value;
     }
     protected static _bigNumberToString(_type: string, value: any): any {
-        return _.isObject(value) && value.isBigNumber ? value.toString() : value;
+        return BigNumber.isBigNumber(value) ? value.toString() : value;
     }
     protected static _lookupConstructorAbi(abi: ContractAbi): ConstructorAbi {
         const constructorAbiIfExists = _.find(
diff --git a/packages/connect/CHANGELOG.json b/packages/connect/CHANGELOG.json
index 8fe9c562f..c2f16d96a 100644
--- a/packages/connect/CHANGELOG.json
+++ b/packages/connect/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "3.0.13",
         "changes": [
diff --git a/packages/contract-wrappers/CHANGELOG.json b/packages/contract-wrappers/CHANGELOG.json
index b9b910165..30199ae1d 100644
--- a/packages/contract-wrappers/CHANGELOG.json
+++ b/packages/contract-wrappers/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "6.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "5.0.1",
         "changes": [
diff --git a/packages/contract-wrappers/package.json b/packages/contract-wrappers/package.json
index 8cee730fe..cc7dc1a3e 100644
--- a/packages/contract-wrappers/package.json
+++ b/packages/contract-wrappers/package.json
@@ -49,7 +49,7 @@
         "@types/web3-provider-engine": "^14.0.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^4.1.0",
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
index ad42cfd4f..cd79a0e5d 100644
--- a/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
@@ -271,7 +271,7 @@ export class ERC20TokenWrapper extends ContractWrapper {
         const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
 
         const fromAddressBalance = await this.getBalanceAsync(normalizedTokenAddress, normalizedFromAddress);
-        if (fromAddressBalance.lessThan(amountInBaseUnits)) {
+        if (fromAddressBalance.isLessThan(amountInBaseUnits)) {
             throw new Error(ContractWrappersError.InsufficientBalanceForTransfer);
         }
 
@@ -327,12 +327,12 @@ export class ERC20TokenWrapper extends ContractWrapper {
             normalizedFromAddress,
             normalizedSenderAddress,
         );
-        if (fromAddressAllowance.lessThan(amountInBaseUnits)) {
+        if (fromAddressAllowance.isLessThan(amountInBaseUnits)) {
             throw new Error(ContractWrappersError.InsufficientAllowanceForTransfer);
         }
 
         const fromAddressBalance = await this.getBalanceAsync(normalizedTokenAddress, normalizedFromAddress);
-        if (fromAddressBalance.lessThan(amountInBaseUnits)) {
+        if (fromAddressBalance.isLessThan(amountInBaseUnits)) {
             throw new Error(ContractWrappersError.InsufficientBalanceForTransfer);
         }
 
diff --git a/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts b/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts
index 1ff130a48..c35b24664 100644
--- a/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts
+++ b/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts
@@ -39,7 +39,7 @@ export class AssetBalanceAndProxyAllowanceFetcher implements AbstractBalanceAndP
                     nestedAssetDataElement,
                     userAddress,
                 )).dividedToIntegerBy(nestedAmountElement);
-                if (_.isUndefined(balance) || nestedAssetBalance.lessThan(balance)) {
+                if (_.isUndefined(balance) || nestedAssetBalance.isLessThan(balance)) {
                     balance = nestedAssetBalance;
                 }
             }
@@ -81,7 +81,7 @@ export class AssetBalanceAndProxyAllowanceFetcher implements AbstractBalanceAndP
                     nestedAssetDataElement,
                     userAddress,
                 )).dividedToIntegerBy(nestedAmountElement);
-                if (_.isUndefined(proxyAllowance) || nestedAssetAllowance.lessThan(proxyAllowance)) {
+                if (_.isUndefined(proxyAllowance) || nestedAssetAllowance.isLessThan(proxyAllowance)) {
                     proxyAllowance = nestedAssetAllowance;
                 }
             }
diff --git a/packages/contract-wrappers/src/utils/exchange_transfer_simulator.ts b/packages/contract-wrappers/src/utils/exchange_transfer_simulator.ts
index f374d509b..4b75ea386 100644
--- a/packages/contract-wrappers/src/utils/exchange_transfer_simulator.ts
+++ b/packages/contract-wrappers/src/utils/exchange_transfer_simulator.ts
@@ -72,10 +72,10 @@ export class ExchangeTransferSimulator {
         }
         const balance = await this._store.getBalanceAsync(tokenAddress, from);
         const proxyAllowance = await this._store.getProxyAllowanceAsync(tokenAddress, from);
-        if (proxyAllowance.lessThan(amountInBaseUnits)) {
+        if (proxyAllowance.isLessThan(amountInBaseUnits)) {
             ExchangeTransferSimulator._throwValidationError(FailureReason.ProxyAllowance, tradeSide, transferType);
         }
-        if (balance.lessThan(amountInBaseUnits)) {
+        if (balance.isLessThan(amountInBaseUnits)) {
             ExchangeTransferSimulator._throwValidationError(FailureReason.Balance, tradeSide, transferType);
         }
         await this._decreaseProxyAllowanceAsync(tokenAddress, from, amountInBaseUnits);
diff --git a/packages/contract-wrappers/src/utils/utils.ts b/packages/contract-wrappers/src/utils/utils.ts
index 0b3270e78..ab69385e7 100644
--- a/packages/contract-wrappers/src/utils/utils.ts
+++ b/packages/contract-wrappers/src/utils/utils.ts
@@ -7,13 +7,15 @@ import { constants } from './constants';
 export const utils = {
     getCurrentUnixTimestampSec(): BigNumber {
         const milisecondsInSecond = 1000;
-        return new BigNumber(Date.now() / milisecondsInSecond).round();
+        return new BigNumber(Date.now() / milisecondsInSecond).integerValue();
     },
     getCurrentUnixTimestampMs(): BigNumber {
         return new BigNumber(Date.now());
     },
     numberPercentageToEtherTokenAmountPercentage(percentage: number): BigNumber {
-        return Web3Wrapper.toBaseUnitAmount(constants.ONE_AMOUNT, constants.ETHER_TOKEN_DECIMALS).mul(percentage);
+        return Web3Wrapper.toBaseUnitAmount(constants.ONE_AMOUNT, constants.ETHER_TOKEN_DECIMALS).multipliedBy(
+            percentage,
+        );
     },
     removeUndefinedProperties<T extends object>(obj: T): Partial<T> {
         return _.pickBy(obj);
diff --git a/packages/contract-wrappers/test/ether_token_wrapper_test.ts b/packages/contract-wrappers/test/ether_token_wrapper_test.ts
index e3efef19d..cc2419aa2 100644
--- a/packages/contract-wrappers/test/ether_token_wrapper_test.ts
+++ b/packages/contract-wrappers/test/ether_token_wrapper_test.ts
@@ -116,7 +116,7 @@ describe('EtherTokenWrapper', () => {
             const preETHBalance = await web3Wrapper.getBalanceInWeiAsync(addressWithETH);
 
             const extraETHBalance = Web3Wrapper.toWei(new BigNumber(5));
-            const overETHBalanceinWei = preETHBalance.add(extraETHBalance);
+            const overETHBalanceinWei = preETHBalance.plus(extraETHBalance);
 
             return expect(
                 contractWrappers.etherToken.depositAsync(wethContractAddress, overETHBalanceinWei, addressWithETH),
@@ -153,7 +153,7 @@ describe('EtherTokenWrapper', () => {
             );
 
             expect(postWETHBalanceInBaseUnits).to.be.bignumber.equal(0);
-            const expectedETHBalance = preETHBalance.add(depositWeiAmount).round(decimalPlaces);
+            const expectedETHBalance = preETHBalance.plus(depositWeiAmount).integerValue(decimalPlaces);
             gasCost = expectedETHBalance.minus(postETHBalance);
             expect(gasCost).to.be.bignumber.lte(MAX_REASONABLE_GAS_COST_IN_WEI);
         });
@@ -165,7 +165,7 @@ describe('EtherTokenWrapper', () => {
             expect(preWETHBalance).to.be.bignumber.equal(0);
 
             // tslint:disable-next-line:custom-no-magic-numbers
-            const overWETHBalance = preWETHBalance.add(999999999);
+            const overWETHBalance = preWETHBalance.plus(999999999);
 
             return expect(
                 contractWrappers.etherToken.withdrawAsync(wethContractAddress, overWETHBalance, addressWithETH),
diff --git a/packages/dev-utils/CHANGELOG.json b/packages/dev-utils/CHANGELOG.json
index 85189d70b..d05e41d2d 100644
--- a/packages/dev-utils/CHANGELOG.json
+++ b/packages/dev-utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.24",
         "changes": [
diff --git a/packages/ethereum-types/CHANGELOG.json b/packages/ethereum-types/CHANGELOG.json
index 6265e01a1..c106d43a9 100644
--- a/packages/ethereum-types/CHANGELOG.json
+++ b/packages/ethereum-types/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.1.6",
         "changes": [
diff --git a/packages/ethereum-types/package.json b/packages/ethereum-types/package.json
index 953b323c6..bd3748058 100644
--- a/packages/ethereum-types/package.json
+++ b/packages/ethereum-types/package.json
@@ -37,7 +37,7 @@
     },
     "dependencies": {
         "@types/node": "*",
-        "bignumber.js": "~4.1.0"
+        "bignumber.js": "~8.0.2"
     },
     "publishConfig": {
         "access": "public"
diff --git a/packages/fill-scenarios/CHANGELOG.json b/packages/fill-scenarios/CHANGELOG.json
index d8f2591a4..beffdd097 100644
--- a/packages/fill-scenarios/CHANGELOG.json
+++ b/packages/fill-scenarios/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.1.2",
         "changes": [
diff --git a/packages/instant/CHANGELOG.json b/packages/instant/CHANGELOG.json
index 537670584..c7348c3c0 100644
--- a/packages/instant/CHANGELOG.json
+++ b/packages/instant/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "version": "2.0.0",
         "changes": [
             {
diff --git a/packages/instant/src/components/order_details.tsx b/packages/instant/src/components/order_details.tsx
index 4db20b13e..3ded50652 100644
--- a/packages/instant/src/components/order_details.tsx
+++ b/packages/instant/src/components/order_details.tsx
@@ -77,7 +77,7 @@ export class OrderDetails extends React.PureComponent<OrderDetailsProps> {
     }
 
     private _hadErrorFetchingUsdPrice(): boolean {
-        return this.props.ethUsdPrice ? this.props.ethUsdPrice.equals(BIG_NUMBER_ZERO) : false;
+        return this.props.ethUsdPrice ? this.props.ethUsdPrice.isEqualTo(BIG_NUMBER_ZERO) : false;
     }
 
     private _totalCostSecondaryValue(): React.ReactNode {
@@ -156,7 +156,7 @@ export class OrderDetails extends React.PureComponent<OrderDetailsProps> {
         return !_.isUndefined(assetTotalInWei) &&
             !_.isUndefined(selectedAssetUnitAmount) &&
             !selectedAssetUnitAmount.eq(BIG_NUMBER_ZERO)
-            ? assetTotalInWei.div(selectedAssetUnitAmount).ceil()
+            ? assetTotalInWei.div(selectedAssetUnitAmount).integerValue(BigNumber.ROUND_CEIL)
             : undefined;
     }
 
diff --git a/packages/instant/src/constants.ts b/packages/instant/src/constants.ts
index bfd9e9098..d407925a3 100644
--- a/packages/instant/src/constants.ts
+++ b/packages/instant/src/constants.ts
@@ -21,7 +21,7 @@ export const NPM_PACKAGE_VERSION = process.env.NPM_PACKAGE_VERSION;
 export const DEFAULT_UNKOWN_ASSET_NAME = '???';
 export const ACCOUNT_UPDATE_INTERVAL_TIME_MS = ONE_SECOND_MS * 5;
 export const BUY_QUOTE_UPDATE_INTERVAL_TIME_MS = ONE_SECOND_MS * 15;
-export const DEFAULT_GAS_PRICE = GWEI_IN_WEI.mul(6);
+export const DEFAULT_GAS_PRICE = GWEI_IN_WEI.multipliedBy(6);
 export const DEFAULT_ESTIMATED_TRANSACTION_TIME_MS = ONE_MINUTE_MS * 2;
 export const MAGIC_TRIGGER_ERROR_INPUT = '0€';
 export const MAGIC_TRIGGER_ERROR_MESSAGE = 'Triggered error';
diff --git a/packages/instant/src/containers/selected_erc20_asset_amount_input.ts b/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
index cb9df527e..4b9993332 100644
--- a/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
+++ b/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
@@ -84,7 +84,7 @@ const mapDispatchToProps = (
         // reset our buy state
         dispatch(actions.setBuyOrderStateNone());
 
-        if (!_.isUndefined(value) && value.greaterThan(0) && !_.isUndefined(asset)) {
+        if (!_.isUndefined(value) && value.isGreaterThan(0) && !_.isUndefined(asset)) {
             // even if it's debounced, give them the illusion it's loading
             dispatch(actions.setQuoteRequestStatePending());
             // tslint:disable-next-line:no-floating-promises
diff --git a/packages/instant/src/redux/async_data.ts b/packages/instant/src/redux/async_data.ts
index 884ab103d..f20fe319f 100644
--- a/packages/instant/src/redux/async_data.ts
+++ b/packages/instant/src/redux/async_data.ts
@@ -99,7 +99,7 @@ export const asyncData = {
         if (
             !_.isUndefined(selectedAssetUnitAmount) &&
             !_.isUndefined(selectedAsset) &&
-            selectedAssetUnitAmount.greaterThan(BIG_NUMBER_ZERO) &&
+            selectedAssetUnitAmount.isGreaterThan(BIG_NUMBER_ZERO) &&
             buyOrderState.processState === OrderProcessState.None &&
             selectedAsset.metaData.assetProxyId === AssetProxyId.ERC20
         ) {
diff --git a/packages/instant/src/util/asset.ts b/packages/instant/src/util/asset.ts
index 709561dbc..b5c97913d 100644
--- a/packages/instant/src/util/asset.ts
+++ b/packages/instant/src/util/asset.ts
@@ -114,15 +114,18 @@ export const assetUtils = {
             const assetName = assetUtils.bestNameForAsset(asset, 'of this asset');
             if (
                 error instanceof InsufficientAssetLiquidityError &&
-                error.amountAvailableToFill.greaterThan(BIG_NUMBER_ZERO)
+                error.amountAvailableToFill.isGreaterThan(BIG_NUMBER_ZERO)
             ) {
                 const unitAmountAvailableToFill = Web3Wrapper.toUnitAmount(
                     error.amountAvailableToFill,
                     asset.metaData.decimals,
                 );
-                const roundedUnitAmountAvailableToFill = unitAmountAvailableToFill.round(2, BigNumber.ROUND_DOWN);
+                const roundedUnitAmountAvailableToFill = unitAmountAvailableToFill.decimalPlaces(
+                    2,
+                    BigNumber.ROUND_DOWN,
+                );
 
-                if (roundedUnitAmountAvailableToFill.greaterThan(BIG_NUMBER_ZERO)) {
+                if (roundedUnitAmountAvailableToFill.isGreaterThan(BIG_NUMBER_ZERO)) {
                     return `There are only ${roundedUnitAmountAvailableToFill} ${assetName} available to buy`;
                 }
             }
diff --git a/packages/instant/src/util/format.ts b/packages/instant/src/util/format.ts
index 4adb63e21..61aeb839f 100644
--- a/packages/instant/src/util/format.ts
+++ b/packages/instant/src/util/format.ts
@@ -25,16 +25,16 @@ export const format = {
         if (_.isUndefined(ethUnitAmount)) {
             return defaultText;
         }
-        let roundedAmount = ethUnitAmount.round(decimalPlaces).toDigits(decimalPlaces);
+        let roundedAmount = ethUnitAmount.decimalPlaces(decimalPlaces).precision(decimalPlaces);
 
-        if (roundedAmount.eq(BIG_NUMBER_ZERO) && ethUnitAmount.greaterThan(BIG_NUMBER_ZERO)) {
+        if (roundedAmount.eq(BIG_NUMBER_ZERO) && ethUnitAmount.isGreaterThan(BIG_NUMBER_ZERO)) {
             // Sometimes for small ETH amounts (i.e. 0.000045) the amount rounded to 4 decimalPlaces is 0
             // If that is the case, show to 1 significant digit
             roundedAmount = new BigNumber(ethUnitAmount.toPrecision(1));
         }
 
         const displayAmount =
-            roundedAmount.greaterThan(BIG_NUMBER_ZERO) && roundedAmount.lessThan(minUnitAmountToDisplay)
+            roundedAmount.isGreaterThan(BIG_NUMBER_ZERO) && roundedAmount.isLessThan(minUnitAmountToDisplay)
                 ? `< ${minUnitAmountToDisplay.toString()}`
                 : roundedAmount.toString();
 
@@ -62,7 +62,7 @@ export const format = {
         if (_.isUndefined(ethUnitAmount) || _.isUndefined(ethUsdPrice)) {
             return defaultText;
         }
-        const rawUsdPrice = ethUnitAmount.mul(ethUsdPrice);
+        const rawUsdPrice = ethUnitAmount.multipliedBy(ethUsdPrice);
         const roundedUsdPrice = rawUsdPrice.toFixed(decimalPlaces);
         if (roundedUsdPrice === '0.00' && rawUsdPrice.gt(BIG_NUMBER_ZERO)) {
             return '<$0.01';
diff --git a/packages/instant/src/util/gas_price_estimator.ts b/packages/instant/src/util/gas_price_estimator.ts
index 332c8d00a..9792b60ba 100644
--- a/packages/instant/src/util/gas_price_estimator.ts
+++ b/packages/instant/src/util/gas_price_estimator.ts
@@ -35,7 +35,7 @@ const fetchFastAmountInWeiAsync = async (): Promise<GasInfo> => {
     const gasPriceInGwei = new BigNumber(gasInfo.fast / 10);
     // Time is in minutes
     const estimatedTimeMs = gasInfo.fastWait * 60 * 1000; // Minutes to MS
-    return { gasPriceInWei: gasPriceInGwei.mul(GWEI_IN_WEI), estimatedTimeMs };
+    return { gasPriceInWei: gasPriceInGwei.multipliedBy(GWEI_IN_WEI), estimatedTimeMs };
 };
 
 export class GasPriceEstimator {
diff --git a/packages/instant/src/util/maybe_big_number.ts b/packages/instant/src/util/maybe_big_number.ts
index 9d3746e10..f48473389 100644
--- a/packages/instant/src/util/maybe_big_number.ts
+++ b/packages/instant/src/util/maybe_big_number.ts
@@ -18,7 +18,7 @@ export const maybeBigNumberUtil = {
     },
     areMaybeBigNumbersEqual: (val1: Maybe<BigNumber>, val2: Maybe<BigNumber>): boolean => {
         if (!_.isUndefined(val1) && !_.isUndefined(val2)) {
-            return val1.equals(val2);
+            return val1.isEqualTo(val2);
         }
         return _.isUndefined(val1) && _.isUndefined(val2);
     },
diff --git a/packages/json-schemas/CHANGELOG.json b/packages/json-schemas/CHANGELOG.json
index 1388b4dca..66de84299 100644
--- a/packages/json-schemas/CHANGELOG.json
+++ b/packages/json-schemas/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "2.1.7",
         "changes": [
diff --git a/packages/metacoin/package.json b/packages/metacoin/package.json
index 4bd2bc66f..3b082f075 100644
--- a/packages/metacoin/package.json
+++ b/packages/metacoin/package.json
@@ -53,7 +53,7 @@
         "@0x/sol-compiler": "^2.0.2",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "npm-run-all": "^4.1.2",
diff --git a/packages/migrations/CHANGELOG.json b/packages/migrations/CHANGELOG.json
index 5962a9886..64ae94b14 100644
--- a/packages/migrations/CHANGELOG.json
+++ b/packages/migrations/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "version": "2.4.0",
         "changes": [
             {
diff --git a/packages/monorepo-scripts/CHANGELOG.json b/packages/monorepo-scripts/CHANGELOG.json
index cebe7ec72..a71bfbd6d 100644
--- a/packages/monorepo-scripts/CHANGELOG.json
+++ b/packages/monorepo-scripts/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "version": "1.0.6",
         "changes": [
             {
diff --git a/packages/order-utils/CHANGELOG.json b/packages/order-utils/CHANGELOG.json
index ace3656c4..08d88da5b 100644
--- a/packages/order-utils/CHANGELOG.json
+++ b/packages/order-utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "3.1.2",
         "changes": [
diff --git a/packages/order-utils/package.json b/packages/order-utils/package.json
index bdcbd2dfc..7a4d4aa84 100644
--- a/packages/order-utils/package.json
+++ b/packages/order-utils/package.json
@@ -41,7 +41,7 @@
         "@types/lodash": "4.14.104",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^4.1.0",
diff --git a/packages/order-utils/src/crypto.ts b/packages/order-utils/src/crypto.ts
index 0f1504a72..8b835ff48 100644
--- a/packages/order-utils/src/crypto.ts
+++ b/packages/order-utils/src/crypto.ts
@@ -1,3 +1,4 @@
+import { BigNumber } from '@0x/utils';
 import BN = require('bn.js');
 import ABI = require('ethereumjs-abi');
 import ethUtil = require('ethereumjs-util');
@@ -24,7 +25,7 @@ export const crypto = {
             const isNumber = _.isFinite(arg);
             if (isNumber) {
                 argTypes.push('uint8');
-            } else if (arg.isBigNumber) {
+            } else if (BigNumber.isBigNumber(arg)) {
                 argTypes.push('uint256');
                 const base = 10;
                 args[i] = new BN(arg.toString(base), base);
diff --git a/packages/order-utils/src/exchange_transfer_simulator.ts b/packages/order-utils/src/exchange_transfer_simulator.ts
index 06621fd9e..922ae8e17 100644
--- a/packages/order-utils/src/exchange_transfer_simulator.ts
+++ b/packages/order-utils/src/exchange_transfer_simulator.ts
@@ -88,14 +88,14 @@ export class ExchangeTransferSimulator {
                 }
                 const balance = await this._store.getBalanceAsync(assetData, from);
                 const proxyAllowance = await this._store.getProxyAllowanceAsync(assetData, from);
-                if (proxyAllowance.lessThan(amountInBaseUnits)) {
+                if (proxyAllowance.isLessThan(amountInBaseUnits)) {
                     ExchangeTransferSimulator._throwValidationError(
                         FailureReason.ProxyAllowance,
                         tradeSide,
                         transferType,
                     );
                 }
-                if (balance.lessThan(amountInBaseUnits)) {
+                if (balance.isLessThan(amountInBaseUnits)) {
                     ExchangeTransferSimulator._throwValidationError(FailureReason.Balance, tradeSide, transferType);
                 }
                 await this._decreaseProxyAllowanceAsync(assetData, from, amountInBaseUnits);
diff --git a/packages/order-utils/src/market_utils.ts b/packages/order-utils/src/market_utils.ts
index fa32f1413..9042551fa 100644
--- a/packages/order-utils/src/market_utils.ts
+++ b/packages/order-utils/src/market_utils.ts
@@ -52,7 +52,7 @@ export const marketUtils = {
         const result = _.reduce(
             orders,
             ({ resultOrders, remainingFillAmount, ordersRemainingFillableMakerAssetAmounts }, order, index) => {
-                if (remainingFillAmount.lessThanOrEqualTo(constants.ZERO_AMOUNT)) {
+                if (remainingFillAmount.isLessThanOrEqualTo(constants.ZERO_AMOUNT)) {
                     return {
                         resultOrders,
                         remainingFillAmount: constants.ZERO_AMOUNT,
@@ -137,7 +137,7 @@ export const marketUtils = {
             (accFees, order, index) => {
                 const makerAssetAmountAvailable = remainingFillableMakerAssetAmounts[index];
                 const feeToFillMakerAssetAmountAvailable = makerAssetAmountAvailable
-                    .mul(order.takerFee)
+                    .multipliedBy(order.takerFee)
                     .dividedToIntegerBy(order.makerAssetAmount);
                 return accFees.plus(feeToFillMakerAssetAmountAvailable);
             },
diff --git a/packages/order-utils/src/order_state_utils.ts b/packages/order-utils/src/order_state_utils.ts
index 389419587..430178b5d 100644
--- a/packages/order-utils/src/order_state_utils.ts
+++ b/packages/order-utils/src/order_state_utils.ts
@@ -214,10 +214,10 @@ export class OrderStateUtils {
         const remainingFillableTakerAssetAmountGivenTakersStatus = orderRelevantTakerState.remainingFillableAssetAmount;
 
         // The min of these two in the actualy max fillable by either party
-        const fillableTakerAssetAmount = BigNumber.min([
+        const fillableTakerAssetAmount = BigNumber.min(
             remainingFillableTakerAssetAmountGivenMakersStatus,
             remainingFillableTakerAssetAmountGivenTakersStatus,
-        ]);
+        );
 
         return fillableTakerAssetAmount;
     }
@@ -260,8 +260,8 @@ export class OrderStateUtils {
             traderAddress,
         );
 
-        const transferrableTraderAssetAmount = BigNumber.min([traderProxyAllowance, traderBalance]);
-        const transferrableFeeAssetAmount = BigNumber.min([traderFeeProxyAllowance, traderFeeBalance]);
+        const transferrableTraderAssetAmount = BigNumber.min(traderProxyAllowance, traderBalance);
+        const transferrableFeeAssetAmount = BigNumber.min(traderFeeProxyAllowance, traderFeeBalance);
 
         const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
         const filledTakerAssetAmount = await this._orderFilledCancelledFetcher.getFilledTakerAmountAsync(orderHash);
@@ -312,7 +312,7 @@ export class OrderStateUtils {
             const tokenAddress = decodedAssetData.tokenAddress;
             balances[tokenAddress] = _.isUndefined(initialBalances[tokenAddress])
                 ? balance
-                : balances[tokenAddress].add(balance);
+                : balances[tokenAddress].plus(balance);
         } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
             for (const assetDataElement of decodedAssetData.nestedAssetData) {
                 balances = await this._getAssetBalancesAsync(assetDataElement, traderAddress, balances);
@@ -335,7 +335,7 @@ export class OrderStateUtils {
             const tokenAddress = decodedAssetData.tokenAddress;
             allowances[tokenAddress] = _.isUndefined(initialAllowances[tokenAddress])
                 ? allowance
-                : allowances[tokenAddress].add(allowance);
+                : allowances[tokenAddress].plus(allowance);
         } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
             for (const assetDataElement of decodedAssetData.nestedAssetData) {
                 allowances = await this._getAssetBalancesAsync(assetDataElement, traderAddress, allowances);
diff --git a/packages/order-utils/src/order_validation_utils.ts b/packages/order-utils/src/order_validation_utils.ts
index ae4291ea8..95215d918 100644
--- a/packages/order-utils/src/order_validation_utils.ts
+++ b/packages/order-utils/src/order_validation_utils.ts
@@ -31,13 +31,13 @@ export class OrderValidationUtils {
         if (denominator.eq(0)) {
             throw new Error('denominator cannot be 0');
         }
-        const remainder = target.mul(numerator).mod(denominator);
+        const remainder = target.multipliedBy(numerator).mod(denominator);
         if (remainder.eq(0)) {
             return false; // no rounding error
         }
 
         // tslint:disable-next-line:custom-no-magic-numbers
-        const errPercentageTimes1000000 = remainder.mul(1000000).div(numerator.mul(target));
+        const errPercentageTimes1000000 = remainder.multipliedBy(1000000).div(numerator.multipliedBy(target));
         // tslint:disable-next-line:custom-no-magic-numbers
         const isError = errPercentageTimes1000000.gt(1000);
         return isError;
@@ -108,7 +108,7 @@ export class OrderValidationUtils {
     }
     private static _validateOrderNotExpiredOrThrow(expirationTimeSeconds: BigNumber): void {
         const currentUnixTimestampSec = utils.getCurrentUnixTimestampSec();
-        if (expirationTimeSeconds.lessThan(currentUnixTimestampSec)) {
+        if (expirationTimeSeconds.isLessThan(currentUnixTimestampSec)) {
             throw new Error(RevertReason.OrderUnfillable);
         }
     }
@@ -216,7 +216,7 @@ export class OrderValidationUtils {
         }
         OrderValidationUtils._validateOrderNotExpiredOrThrow(signedOrder.expirationTimeSeconds);
         const remainingTakerTokenAmount = signedOrder.takerAssetAmount.minus(filledTakerTokenAmount);
-        const desiredFillTakerTokenAmount = remainingTakerTokenAmount.lessThan(fillTakerAssetAmount)
+        const desiredFillTakerTokenAmount = remainingTakerTokenAmount.isLessThan(fillTakerAssetAmount)
             ? remainingTakerTokenAmount
             : fillTakerAssetAmount;
         try {
diff --git a/packages/order-utils/src/rate_utils.ts b/packages/order-utils/src/rate_utils.ts
index 416e00c67..dacdbd5a2 100644
--- a/packages/order-utils/src/rate_utils.ts
+++ b/packages/order-utils/src/rate_utils.ts
@@ -22,7 +22,7 @@ export const rateUtils = {
             feeRate.gte(constants.ZERO_AMOUNT),
             `Expected feeRate: ${feeRate} to be greater than or equal to 0`,
         );
-        const takerAssetAmountNeededToPayForFees = order.takerFee.mul(feeRate);
+        const takerAssetAmountNeededToPayForFees = order.takerFee.multipliedBy(feeRate);
         const totalTakerAssetAmount = takerAssetAmountNeededToPayForFees.plus(order.takerAssetAmount);
         const rate = totalTakerAssetAmount.div(order.makerAssetAmount);
         return rate;
@@ -35,9 +35,9 @@ export const rateUtils = {
      */
     getFeeAdjustedRateOfFeeOrder(feeOrder: Order): BigNumber {
         assert.doesConformToSchema('feeOrder', feeOrder, schemas.orderSchema);
-        const zrxAmountAfterFees = feeOrder.makerAssetAmount.sub(feeOrder.takerFee);
+        const zrxAmountAfterFees = feeOrder.makerAssetAmount.minus(feeOrder.takerFee);
         assert.assert(
-            zrxAmountAfterFees.greaterThan(constants.ZERO_AMOUNT),
+            zrxAmountAfterFees.isGreaterThan(constants.ZERO_AMOUNT),
             `Expected takerFee: ${JSON.stringify(feeOrder.takerFee)} to be less than makerAssetAmount: ${JSON.stringify(
                 feeOrder.makerAssetAmount,
             )}`,
diff --git a/packages/order-utils/src/remaining_fillable_calculator.ts b/packages/order-utils/src/remaining_fillable_calculator.ts
index 052eafa1d..92ffc8e80 100644
--- a/packages/order-utils/src/remaining_fillable_calculator.ts
+++ b/packages/order-utils/src/remaining_fillable_calculator.ts
@@ -39,15 +39,15 @@ export class RemainingFillableCalculator {
     private _hasSufficientFundsForFeeAndTransferAmount(): boolean {
         if (this._isTraderAssetZRX) {
             const totalZRXTransferAmountRequired = this._remainingOrderAssetAmount.plus(this._remainingOrderFeeAmount);
-            const hasSufficientFunds = this._transferrableAssetAmount.greaterThanOrEqualTo(
+            const hasSufficientFunds = this._transferrableAssetAmount.isGreaterThanOrEqualTo(
                 totalZRXTransferAmountRequired,
             );
             return hasSufficientFunds;
         } else {
-            const hasSufficientFundsForTransferAmount = this._transferrableAssetAmount.greaterThanOrEqualTo(
+            const hasSufficientFundsForTransferAmount = this._transferrableAssetAmount.isGreaterThanOrEqualTo(
                 this._remainingOrderAssetAmount,
             );
-            const hasSufficientFundsForFeeAmount = this._transferrableFeeAmount.greaterThanOrEqualTo(
+            const hasSufficientFundsForFeeAmount = this._transferrableFeeAmount.isGreaterThanOrEqualTo(
                 this._remainingOrderFeeAmount,
             );
             const hasSufficientFunds = hasSufficientFundsForTransferAmount && hasSufficientFundsForFeeAmount;
diff --git a/packages/order-utils/src/salt.ts b/packages/order-utils/src/salt.ts
index ff47ab5d2..95df66c99 100644
--- a/packages/order-utils/src/salt.ts
+++ b/packages/order-utils/src/salt.ts
@@ -13,6 +13,6 @@ export function generatePseudoRandomSalt(): BigNumber {
     // Source: https://mikemcl.github.io/bignumber.js/#random
     const randomNumber = BigNumber.random(MAX_DIGITS_IN_UNSIGNED_256_INT);
     const factor = new BigNumber(10).pow(MAX_DIGITS_IN_UNSIGNED_256_INT - 1);
-    const salt = randomNumber.times(factor).round();
+    const salt = randomNumber.times(factor).integerValue();
     return salt;
 }
diff --git a/packages/order-utils/src/utils.ts b/packages/order-utils/src/utils.ts
index 6b2261001..64195dbed 100644
--- a/packages/order-utils/src/utils.ts
+++ b/packages/order-utils/src/utils.ts
@@ -10,13 +10,13 @@ export const utils = {
     },
     getCurrentUnixTimestampSec(): BigNumber {
         const milisecondsInSecond = 1000;
-        return new BigNumber(Date.now() / milisecondsInSecond).round();
+        return new BigNumber(Date.now() / milisecondsInSecond).integerValue();
     },
     getPartialAmountFloor(numerator: BigNumber, denominator: BigNumber, target: BigNumber): BigNumber {
         const fillMakerTokenAmount = numerator
-            .mul(target)
+            .multipliedBy(target)
             .div(denominator)
-            .round(0);
+            .integerValue(0);
         return fillMakerTokenAmount;
     },
 };
diff --git a/packages/order-utils/test/remaining_fillable_calculator_test.ts b/packages/order-utils/test/remaining_fillable_calculator_test.ts
index c55a76def..affad8f1c 100644
--- a/packages/order-utils/test/remaining_fillable_calculator_test.ts
+++ b/packages/order-utils/test/remaining_fillable_calculator_test.ts
@@ -162,7 +162,7 @@ describe('RemainingFillableCalculator', () => {
                     remainingMakeAssetAmount,
                 );
                 const calculatedFillableAmount = calculator.computeRemainingFillable();
-                expect(calculatedFillableAmount.lessThanOrEqualTo(transferrableMakeAssetAmount)).to.be.true();
+                expect(calculatedFillableAmount.isLessThanOrEqualTo(transferrableMakeAssetAmount)).to.be.true();
                 expect(calculatedFillableAmount).to.be.bignumber.greaterThan(new BigNumber(0));
                 const orderToFeeRatio = signedOrder.makerAssetAmount.dividedBy(signedOrder.makerFee);
                 const calculatedFeeAmount = calculatedFillableAmount.dividedBy(orderToFeeRatio);
diff --git a/packages/order-utils/test/signature_utils_test.ts b/packages/order-utils/test/signature_utils_test.ts
index 84e5559a9..937382056 100644
--- a/packages/order-utils/test/signature_utils_test.ts
+++ b/packages/order-utils/test/signature_utils_test.ts
@@ -132,10 +132,10 @@ describe('Signature utils', () => {
         });
         it('generates salt in range [0..2^256)', () => {
             const salt = generatePseudoRandomSalt();
-            expect(salt.greaterThanOrEqualTo(0)).to.be.true();
+            expect(salt.isGreaterThanOrEqualTo(0)).to.be.true();
             // tslint:disable-next-line:custom-no-magic-numbers
             const twoPow256 = new BigNumber(2).pow(256);
-            expect(salt.lessThan(twoPow256)).to.be.true();
+            expect(salt.isLessThan(twoPow256)).to.be.true();
         });
     });
     describe('#ecSignOrderAsync', () => {
diff --git a/packages/order-watcher/CHANGELOG.json b/packages/order-watcher/CHANGELOG.json
index 29fe4e723..585bb48e6 100644
--- a/packages/order-watcher/CHANGELOG.json
+++ b/packages/order-watcher/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "2.4.3",
         "changes": [
diff --git a/packages/order-watcher/package.json b/packages/order-watcher/package.json
index 0f2464eae..895c64813 100644
--- a/packages/order-watcher/package.json
+++ b/packages/order-watcher/package.json
@@ -49,7 +49,7 @@
         "@types/sinon": "^2.2.2",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^4.1.0",
diff --git a/packages/order-watcher/src/order_watcher/expiration_watcher.ts b/packages/order-watcher/src/order_watcher/expiration_watcher.ts
index ad20a6e3f..82590efde 100644
--- a/packages/order-watcher/src/order_watcher/expiration_watcher.ts
+++ b/packages/order-watcher/src/order_watcher/expiration_watcher.ts
@@ -73,7 +73,7 @@ export class ExpirationWatcher {
                 break;
             }
             const nextOrderHashToExpire = this._orderHashByExpirationRBTree.min();
-            const hasNoExpiredOrders = this._expiration[nextOrderHashToExpire].greaterThan(
+            const hasNoExpiredOrders = this._expiration[nextOrderHashToExpire].isGreaterThan(
                 currentUnixTimestampMs.plus(this._expirationMarginMs),
             );
             const isSubscriptionActive = _.isUndefined(this._orderExpirationCheckingIntervalIdIfExists);
diff --git a/packages/order-watcher/src/utils/utils.ts b/packages/order-watcher/src/utils/utils.ts
index a7d10aaf9..9c3849ff1 100644
--- a/packages/order-watcher/src/utils/utils.ts
+++ b/packages/order-watcher/src/utils/utils.ts
@@ -3,7 +3,7 @@ import { BigNumber } from '@0x/utils';
 export const utils = {
     getCurrentUnixTimestampSec(): BigNumber {
         const milisecondsInASecond = 1000;
-        return new BigNumber(Date.now() / milisecondsInASecond).round();
+        return new BigNumber(Date.now() / milisecondsInASecond).integerValue();
     },
     getCurrentUnixTimestampMs(): BigNumber {
         return new BigNumber(Date.now());
diff --git a/packages/order-watcher/test/order_watcher_test.ts b/packages/order-watcher/test/order_watcher_test.ts
index 41dc884d5..28b564b32 100644
--- a/packages/order-watcher/test/order_watcher_test.ts
+++ b/packages/order-watcher/test/order_watcher_test.ts
@@ -317,7 +317,7 @@ describe('OrderWatcher', () => {
                     const validOrderState = orderState as OrderStateValid;
                     expect(validOrderState.orderHash).to.be.equal(orderHash);
                     const orderRelevantState = validOrderState.orderRelevantState;
-                    const remainingMakerBalance = makerBalance.sub(fillAmountInBaseUnits);
+                    const remainingMakerBalance = makerBalance.minus(fillAmountInBaseUnits);
                     const remainingFillable = fillableAmount.minus(fillAmountInBaseUnits);
                     expect(orderRelevantState.remainingFillableMakerAssetAmount).to.be.bignumber.equal(
                         remainingFillable,
@@ -434,7 +434,7 @@ describe('OrderWatcher', () => {
                     );
 
                     const remainingAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(1), decimals);
-                    const transferAmount = makerBalance.sub(remainingAmount);
+                    const transferAmount = makerBalance.minus(remainingAmount);
                     await orderWatcher.addOrderAsync(signedOrder);
 
                     const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
@@ -475,7 +475,7 @@ describe('OrderWatcher', () => {
                     const remainingFeeAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(3), decimals);
 
                     const remainingTokenAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(4), decimals);
-                    const transferTokenAmount = makerFee.sub(remainingTokenAmount);
+                    const transferTokenAmount = makerFee.minus(remainingTokenAmount);
                     await orderWatcher.addOrderAsync(signedOrder);
 
                     const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
diff --git a/packages/pipeline/package.json b/packages/pipeline/package.json
index 988dd8b74..908734687 100644
--- a/packages/pipeline/package.json
+++ b/packages/pipeline/package.json
@@ -32,7 +32,7 @@
         "@types/ramda": "^0.25.38",
         "chai": "^4.1.2",
         "chai-as-promised": "^7.1.1",
-        "chai-bignumber": "^2.0.2",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "mocha": "^5.2.0",
         "tslint": "5.11.0",
diff --git a/packages/pipeline/src/utils/transformers/number_to_bigint.ts b/packages/pipeline/src/utils/transformers/number_to_bigint.ts
index 9736d7c18..8fbd52093 100644
--- a/packages/pipeline/src/utils/transformers/number_to_bigint.ts
+++ b/packages/pipeline/src/utils/transformers/number_to_bigint.ts
@@ -19,7 +19,7 @@ export class NumberToBigIntTransformer implements ValueTransformer {
 
     // tslint:disable-next-line:prefer-function-over-method
     public from(value: string): number {
-        if (new BigNumber(value).greaterThan(Number.MAX_SAFE_INTEGER)) {
+        if (new BigNumber(value).isGreaterThan(Number.MAX_SAFE_INTEGER)) {
             throw new Error(
                 `Attempted to convert PostgreSQL bigint value (${value}) to JavaScript number type but it is too big to safely convert`,
             );
diff --git a/packages/react-docs/CHANGELOG.json b/packages/react-docs/CHANGELOG.json
index 101da65c7..8b418fc11 100644
--- a/packages/react-docs/CHANGELOG.json
+++ b/packages/react-docs/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.25",
         "changes": [
diff --git a/packages/react-shared/CHANGELOG.json b/packages/react-shared/CHANGELOG.json
index a6d2c4fa0..99a8779ac 100644
--- a/packages/react-shared/CHANGELOG.json
+++ b/packages/react-shared/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.1.2",
         "changes": [
diff --git a/packages/sol-compiler/CHANGELOG.json b/packages/sol-compiler/CHANGELOG.json
index d7dd5a454..672939a4a 100644
--- a/packages/sol-compiler/CHANGELOG.json
+++ b/packages/sol-compiler/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "2.0.2",
         "changes": [
diff --git a/packages/sol-compiler/package.json b/packages/sol-compiler/package.json
index 26c8e8833..0b53cffd5 100644
--- a/packages/sol-compiler/package.json
+++ b/packages/sol-compiler/package.json
@@ -51,7 +51,7 @@
         "@types/semver": "^5.5.0",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.2",
+        "chai-bignumber": "^3.0.0",
         "copyfiles": "^2.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
diff --git a/packages/sol-coverage/CHANGELOG.json b/packages/sol-coverage/CHANGELOG.json
index d2ad03030..550ca2feb 100644
--- a/packages/sol-coverage/CHANGELOG.json
+++ b/packages/sol-coverage/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.3",
         "changes": [
diff --git a/packages/sol-doc/CHANGELOG.json b/packages/sol-doc/CHANGELOG.json
index f95702ee4..662915faf 100644
--- a/packages/sol-doc/CHANGELOG.json
+++ b/packages/sol-doc/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.14",
         "changes": [
diff --git a/packages/sol-doc/package.json b/packages/sol-doc/package.json
index dee6ef2e5..179f45e81 100644
--- a/packages/sol-doc/package.json
+++ b/packages/sol-doc/package.json
@@ -37,7 +37,7 @@
         "@0x/tslint-config": "^2.0.2",
         "chai": "^4.1.2",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.2",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^5.2.0",
diff --git a/packages/sol-profiler/CHANGELOG.json b/packages/sol-profiler/CHANGELOG.json
index d2ad03030..550ca2feb 100644
--- a/packages/sol-profiler/CHANGELOG.json
+++ b/packages/sol-profiler/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.3",
         "changes": [
diff --git a/packages/sol-resolver/CHANGELOG.json b/packages/sol-resolver/CHANGELOG.json
index e5f4a8ac1..f5a005fd4 100644
--- a/packages/sol-resolver/CHANGELOG.json
+++ b/packages/sol-resolver/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.2.3",
         "changes": [
diff --git a/packages/sol-trace/CHANGELOG.json b/packages/sol-trace/CHANGELOG.json
index d2ad03030..550ca2feb 100644
--- a/packages/sol-trace/CHANGELOG.json
+++ b/packages/sol-trace/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547747677,
         "version": "1.0.3",
         "changes": [
diff --git a/packages/sol-tracing-utils/CHANGELOG.json b/packages/sol-tracing-utils/CHANGELOG.json
index 7e98003f7..ef96dc69b 100644
--- a/packages/sol-tracing-utils/CHANGELOG.json
+++ b/packages/sol-tracing-utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "5.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "version": "4.0.1",
         "changes": [
             {
diff --git a/packages/sra-spec/CHANGELOG.json b/packages/sra-spec/CHANGELOG.json
index 3f2a9fbc1..e22a3b0e4 100644
--- a/packages/sra-spec/CHANGELOG.json
+++ b/packages/sra-spec/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.0.16",
         "changes": [
diff --git a/packages/subproviders/CHANGELOG.json b/packages/subproviders/CHANGELOG.json
index dd4dccf4e..68f2e4110 100644
--- a/packages/subproviders/CHANGELOG.json
+++ b/packages/subproviders/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "2.1.11",
         "changes": [
diff --git a/packages/testnet-faucets/src/ts/dispense_asset_tasks.ts b/packages/testnet-faucets/src/ts/dispense_asset_tasks.ts
index 32f5cb623..58caeeeaa 100644
--- a/packages/testnet-faucets/src/ts/dispense_asset_tasks.ts
+++ b/packages/testnet-faucets/src/ts/dispense_asset_tasks.ts
@@ -19,7 +19,7 @@ export const dispenseAssetTasks = {
             logUtils.log(`Processing ETH ${recipientAddress}`);
             const userBalance = await web3Wrapper.getBalanceInWeiAsync(recipientAddress);
             const maxAmountInWei = Web3Wrapper.toWei(new BigNumber(DISPENSE_MAX_AMOUNT_ETHER));
-            if (userBalance.greaterThanOrEqualTo(maxAmountInWei)) {
+            if (userBalance.isGreaterThanOrEqualTo(maxAmountInWei)) {
                 logUtils.log(
                     `User exceeded ETH balance maximum (${maxAmountInWei}) ${recipientAddress} ${userBalance} `,
                 );
@@ -55,7 +55,7 @@ export const dispenseAssetTasks = {
                 new BigNumber(DISPENSE_MAX_AMOUNT_TOKEN),
                 tokenIfExists.decimals,
             );
-            if (userBalanceBaseUnits.greaterThanOrEqualTo(maxAmountBaseUnits)) {
+            if (userBalanceBaseUnits.isGreaterThanOrEqualTo(maxAmountBaseUnits)) {
                 logUtils.log(
                     `User exceeded token balance maximum (${maxAmountBaseUnits}) ${recipientAddress} ${userBalanceBaseUnits} `,
                 );
diff --git a/packages/testnet-faucets/src/ts/handler.ts b/packages/testnet-faucets/src/ts/handler.ts
index 8f642d4b0..533e1f8b3 100644
--- a/packages/testnet-faucets/src/ts/handler.ts
+++ b/packages/testnet-faucets/src/ts/handler.ts
@@ -178,8 +178,10 @@ export class Handler {
             exchangeAddress: networkConfig.contractWrappers.exchange.address,
             feeRecipientAddress: NULL_ADDRESS,
             senderAddress: NULL_ADDRESS,
-            // tslint:disable-next-line:custom-no-magic-numbers
-            expirationTimeSeconds: new BigNumber(Date.now() + FIVE_DAYS_IN_MS).div(1000).floor(),
+            expirationTimeSeconds: new BigNumber(Date.now() + FIVE_DAYS_IN_MS)
+                // tslint:disable-next-line:custom-no-magic-numbers
+                .div(1000)
+                .integerValue(BigNumber.ROUND_FLOOR),
         };
         const orderHash = orderHashUtils.getOrderHashHex(order);
         const signature = await signatureUtils.ecSignHashAsync(
diff --git a/packages/tslint-config/CHANGELOG.json b/packages/tslint-config/CHANGELOG.json
index fe34592fd..34ea6aa6b 100644
--- a/packages/tslint-config/CHANGELOG.json
+++ b/packages/tslint-config/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "2.0.2",
         "changes": [
diff --git a/packages/types/CHANGELOG.json b/packages/types/CHANGELOG.json
index 40a46ac84..7a6d205ee 100644
--- a/packages/types/CHANGELOG.json
+++ b/packages/types/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "1.5.2",
         "changes": [
diff --git a/packages/types/package.json b/packages/types/package.json
index 2fea809bc..440f05423 100644
--- a/packages/types/package.json
+++ b/packages/types/package.json
@@ -31,7 +31,7 @@
     },
     "dependencies": {
         "@types/node": "*",
-        "bignumber.js": "~4.1.0",
+        "bignumber.js": "~8.0.2",
         "ethereum-types": "^1.1.6"
     },
     "publishConfig": {
diff --git a/packages/typescript-typings/CHANGELOG.json b/packages/typescript-typings/CHANGELOG.json
index cc7ef7fa4..e3ae60231 100644
--- a/packages/typescript-typings/CHANGELOG.json
+++ b/packages/typescript-typings/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "3.0.8",
         "changes": [
diff --git a/packages/typescript-typings/package.json b/packages/typescript-typings/package.json
index 6640760e4..01cab8c63 100644
--- a/packages/typescript-typings/package.json
+++ b/packages/typescript-typings/package.json
@@ -26,7 +26,7 @@
     "dependencies": {
         "@types/bn.js": "^4.11.0",
         "@types/react": "*",
-        "bignumber.js": "~4.1.0",
+        "bignumber.js": "~8.0.2",
         "ethereum-types": "^1.1.6",
         "popper.js": "1.14.3"
     },
diff --git a/packages/utils/CHANGELOG.json b/packages/utils/CHANGELOG.json
index 851c106d8..0fb199e58 100644
--- a/packages/utils/CHANGELOG.json
+++ b/packages/utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "3.0.1",
         "changes": [
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 315f5a08f..b6be39210 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -34,7 +34,7 @@
         "@types/mocha": "^2.2.42",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^4.1.0",
@@ -48,7 +48,7 @@
         "@0x/typescript-typings": "^3.0.8",
         "@types/node": "*",
         "abortcontroller-polyfill": "^1.1.9",
-        "bignumber.js": "~4.1.0",
+        "bignumber.js": "~8.0.2",
         "chalk": "^2.4.1",
         "detect-node": "2.0.3",
         "ethereum-types": "^1.1.6",
diff --git a/packages/utils/src/abi_decoder.ts b/packages/utils/src/abi_decoder.ts
index 2da46db35..28b6418d8 100644
--- a/packages/utils/src/abi_decoder.ts
+++ b/packages/utils/src/abi_decoder.ts
@@ -69,7 +69,7 @@ export class AbiDecoder {
             }
             if (param.type === SolidityTypes.Address) {
                 const baseHex = 16;
-                value = addressUtils.padZeros(new BigNumber(value).toString(baseHex));
+                value = addressUtils.padZeros(new BigNumber((value as string).toLowerCase()).toString(baseHex));
             } else if (param.type === SolidityTypes.Uint256 || param.type === SolidityTypes.Uint) {
                 value = new BigNumber(value);
             } else if (param.type === SolidityTypes.Uint8) {
diff --git a/packages/utils/src/abi_encoder/evm_data_types/bool.ts b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
index 7f91f34e6..23298bc88 100644
--- a/packages/utils/src/abi_encoder/evm_data_types/bool.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
@@ -37,11 +37,11 @@ export class BoolDataType extends AbstractBlobDataType {
         const valueBuf = calldata.popWord();
         const valueHex = ethUtil.bufferToHex(valueBuf);
         const valueNumber = new BigNumber(valueHex, constants.HEX_BASE);
-        if (!(valueNumber.equals(0) || valueNumber.equals(1))) {
+        if (!(valueNumber.isEqualTo(0) || valueNumber.isEqualTo(1))) {
             throw new Error(`Failed to decode boolean. Expected 0x0 or 0x1, got ${valueHex}`);
         }
         /* tslint:disable boolean-naming */
-        const value: boolean = !valueNumber.equals(0);
+        const value: boolean = !valueNumber.isEqualTo(0);
         /* tslint:enable boolean-naming */
         return value;
     }
diff --git a/packages/utils/src/abi_encoder/evm_data_types/int.ts b/packages/utils/src/abi_encoder/evm_data_types/int.ts
index cc3164b18..f8be1f778 100644
--- a/packages/utils/src/abi_encoder/evm_data_types/int.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types/int.ts
@@ -38,8 +38,8 @@ export class IntDataType extends AbstractBlobDataType {
             throw new Error(`Tried to instantiate Int with bad input: ${dataItem}`);
         }
         this._width = IntDataType._decodeWidthFromType(dataItem.type);
-        this._minValue = new BigNumber(2).toPower(this._width - 1).times(-1);
-        this._maxValue = new BigNumber(2).toPower(this._width - 1).sub(1);
+        this._minValue = new BigNumber(2).exponentiatedBy(this._width - 1).times(-1);
+        this._maxValue = new BigNumber(2).exponentiatedBy(this._width - 1).minus(1);
     }
 
     public encodeValue(value: BigNumber | string | number): Buffer {
diff --git a/packages/utils/src/abi_encoder/evm_data_types/uint.ts b/packages/utils/src/abi_encoder/evm_data_types/uint.ts
index 8e382e8dc..a82aa789e 100644
--- a/packages/utils/src/abi_encoder/evm_data_types/uint.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types/uint.ts
@@ -38,7 +38,7 @@ export class UIntDataType extends AbstractBlobDataType {
             throw new Error(`Tried to instantiate UInt with bad input: ${dataItem}`);
         }
         this._width = UIntDataType._decodeWidthFromType(dataItem.type);
-        this._maxValue = new BigNumber(2).toPower(this._width).sub(1);
+        this._maxValue = new BigNumber(2).exponentiatedBy(this._width).minus(1);
     }
 
     public encodeValue(value: BigNumber | string | number): Buffer {
diff --git a/packages/utils/src/abi_encoder/utils/math.ts b/packages/utils/src/abi_encoder/utils/math.ts
index d84983c5b..a2a79e2a8 100644
--- a/packages/utils/src/abi_encoder/utils/math.ts
+++ b/packages/utils/src/abi_encoder/utils/math.ts
@@ -1,7 +1,7 @@
-import BigNumber from 'bignumber.js';
 import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
+import { BigNumber } from '../../configured_bignumber';
 import { constants } from '../utils/constants';
 
 function sanityCheckBigNumberRange(
@@ -10,10 +10,12 @@ function sanityCheckBigNumberRange(
     maxValue: BigNumber,
 ): void {
     const value = new BigNumber(value_, 10);
-    if (value.greaterThan(maxValue)) {
+    if (value.isGreaterThan(maxValue)) {
         throw new Error(`Tried to assign value of ${value}, which exceeds max value of ${maxValue}`);
-    } else if (value.lessThan(minValue)) {
+    } else if (value.isLessThan(minValue)) {
         throw new Error(`Tried to assign value of ${value}, which exceeds min value of ${minValue}`);
+    } else if (value.isNaN()) {
+        throw new Error(`Tried to assign NaN value`);
     }
 }
 function bigNumberToPaddedBuffer(value: BigNumber): Buffer {
@@ -30,7 +32,7 @@ function bigNumberToPaddedBuffer(value: BigNumber): Buffer {
 export function encodeNumericValue(value_: BigNumber | string | number): Buffer {
     const value = new BigNumber(value_, 10);
     // Case 1/2: value is non-negative
-    if (value.greaterThanOrEqualTo(0)) {
+    if (value.isGreaterThanOrEqualTo(0)) {
         const encodedPositiveValue = bigNumberToPaddedBuffer(value);
         return encodedPositiveValue;
     }
@@ -74,7 +76,7 @@ export function decodeNumericValue(encodedValue: Buffer, minValue: BigNumber): B
     const valueHex = ethUtil.bufferToHex(encodedValue);
     // Case 1/3: value is definitely non-negative because of numeric boundaries
     const value = new BigNumber(valueHex, constants.HEX_BASE);
-    if (!minValue.lessThan(0)) {
+    if (!minValue.isLessThan(0)) {
         return value;
     }
     // Case 2/3: value is non-negative because there is no leading 1 (encoded as two's-complement)
diff --git a/packages/utils/src/sign_typed_data_utils.ts b/packages/utils/src/sign_typed_data_utils.ts
index 6963b9084..adb66622d 100644
--- a/packages/utils/src/sign_typed_data_utils.ts
+++ b/packages/utils/src/sign_typed_data_utils.ts
@@ -1,8 +1,9 @@
+import { EIP712Object, EIP712ObjectValue, EIP712TypedData, EIP712Types } from '@0x/types';
 import * as ethUtil from 'ethereumjs-util';
 import * as ethers from 'ethers';
 import * as _ from 'lodash';
 
-import { EIP712Object, EIP712ObjectValue, EIP712TypedData, EIP712Types } from '@0x/types';
+import { BigNumber } from './configured_bignumber';
 
 export const signTypedDataUtils = {
     /**
@@ -70,7 +71,7 @@ export const signTypedDataUtils = {
         return ethers.utils.defaultAbiCoder.encode(encodedTypes, encodedValues);
     },
     _normalizeValue(type: string, value: any): EIP712ObjectValue {
-        const normalizedValue = type === 'uint256' && _.isObject(value) && value.isBigNumber ? value.toString() : value;
+        const normalizedValue = type === 'uint256' && BigNumber.isBigNumber(value) ? value.toString() : value;
         return normalizedValue;
     },
     _typeHash(primaryType: string, types: EIP712Types): Buffer {
diff --git a/packages/utils/test/abi_encoder/evm_data_types_test.ts b/packages/utils/test/abi_encoder/evm_data_types_test.ts
index 54d536a7e..4814ce28b 100644
--- a/packages/utils/test/abi_encoder/evm_data_types_test.ts
+++ b/packages/utils/test/abi_encoder/evm_data_types_test.ts
@@ -205,7 +205,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
             // Encode Args and validate result
             expect(() => {
                 dataType.encode(args, encodingRules);
-            }).to.throw();
+            }).to.throw('Tried to assign NaN value');
         });
     });
 
diff --git a/packages/web3-wrapper/CHANGELOG.json b/packages/web3-wrapper/CHANGELOG.json
index b9d5a37b1..e05879ba8 100644
--- a/packages/web3-wrapper/CHANGELOG.json
+++ b/packages/web3-wrapper/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "4.0.0",
+        "changes": [
+            {
+                "note": "Upgrade the bignumber.js to v8.0.2",
+                "pr": 1517
+            }
+        ]
+    },
+    {
         "timestamp": 1547561734,
         "version": "3.2.4",
         "changes": [
diff --git a/packages/web3-wrapper/package.json b/packages/web3-wrapper/package.json
index ce9c41ae7..1ef7f91c6 100644
--- a/packages/web3-wrapper/package.json
+++ b/packages/web3-wrapper/package.json
@@ -41,7 +41,7 @@
         "@types/lodash": "4.14.104",
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
-        "chai-bignumber": "^2.0.1",
+        "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
         "ganache-core": "0xProject/ganache-core#monorepo-dep",
         "make-promises-safe": "^1.1.0",
diff --git a/packages/web3-wrapper/src/utils.ts b/packages/web3-wrapper/src/utils.ts
index c68587632..1aba3c75a 100644
--- a/packages/web3-wrapper/src/utils.ts
+++ b/packages/web3-wrapper/src/utils.ts
@@ -2,10 +2,6 @@ import { BigNumber } from '@0x/utils';
 import * as _ from 'lodash';
 
 export const utils = {
-    isBigNumber(value: any): boolean {
-        const isBigNumber = _.isObject(value) && value.isBigNumber;
-        return isBigNumber;
-    },
     convertHexToNumber(value: string): number {
         const valueBigNumber = new BigNumber(value);
         const valueNumber = valueBigNumber.toNumber();
@@ -20,7 +16,7 @@ export const utils = {
     },
     convertAmountToBigNumber(value: string | number | BigNumber): BigNumber {
         const num = value || 0;
-        const isBigNumber = utils.isBigNumber(num);
+        const isBigNumber = BigNumber.isBigNumber(num);
         if (isBigNumber) {
             return num as BigNumber;
         }
@@ -37,7 +33,7 @@ export const utils = {
         const hexBase = 16;
         const valueHex = valueBigNumber.toString(hexBase);
 
-        return valueBigNumber.lessThan(0) ? `-0x${valueHex.substr(1)}` : `0x${valueHex}`;
+        return valueBigNumber.isLessThan(0) ? `-0x${valueHex.substr(1)}` : `0x${valueHex}`;
     },
     numberToHex(value: number): string {
         if (!isFinite(value) && !utils.isHexStrict(value)) {
diff --git a/packages/web3-wrapper/test/web3_wrapper_test.ts b/packages/web3-wrapper/test/web3_wrapper_test.ts
index 935c67636..b6985c155 100644
--- a/packages/web3-wrapper/test/web3_wrapper_test.ts
+++ b/packages/web3-wrapper/test/web3_wrapper_test.ts
@@ -1,10 +1,10 @@
+import { BigNumber } from '@0x/utils';
 import * as chai from 'chai';
 import { BlockParamLiteral, JSONRPCErrorCallback, JSONRPCRequestPayload, TransactionReceipt } from 'ethereum-types';
 import * as Ganache from 'ganache-core';
 import * as _ from 'lodash';
 import 'mocha';
 
-import { utils } from '../src/utils';
 import { Web3Wrapper } from '../src/web3_wrapper';
 
 import { chaiSetup } from './utils/chai_setup';
@@ -118,7 +118,7 @@ describe('Web3Wrapper tests', () => {
                 throw new Error('Expected block to exist');
             }
             expect(blockIfExists.number).to.be.equal(0);
-            expect(utils.isBigNumber(blockIfExists.difficulty)).to.equal(true);
+            expect(BigNumber.isBigNumber(blockIfExists.difficulty)).to.equal(true);
             expect(_.isNumber(blockIfExists.gasLimit)).to.equal(true);
         });
         it('gets block when supplied a block number', async () => {
@@ -151,7 +151,7 @@ describe('Web3Wrapper tests', () => {
             const blockParamLiteral = BlockParamLiteral.Earliest;
             const block = await web3Wrapper.getBlockWithTransactionDataAsync(blockParamLiteral);
             expect(block.number).to.be.equal(0);
-            expect(utils.isBigNumber(block.difficulty)).to.equal(true);
+            expect(BigNumber.isBigNumber(block.difficulty)).to.equal(true);
             expect(_.isNumber(block.gasLimit)).to.equal(true);
         });
         it('should throw if supplied invalid blockParam value', async () => {
diff --git a/packages/website/ts/blockchain.ts b/packages/website/ts/blockchain.ts
index 37f746f7c..ea5a59340 100644
--- a/packages/website/ts/blockchain.ts
+++ b/packages/website/ts/blockchain.ts
@@ -944,7 +944,7 @@ export class Blockchain {
         try {
             const gasInfo = await backendClient.getGasInfoAsync();
             const gasPriceInGwei = new BigNumber(gasInfo.fast / 10);
-            const gasPriceInWei = gasPriceInGwei.mul(1000000000);
+            const gasPriceInWei = gasPriceInGwei.multipliedBy(1000000000);
             this._defaultGasPrice = gasPriceInWei;
         } catch (err) {
             return;
diff --git a/packages/website/ts/components/fill_order.tsx b/packages/website/ts/components/fill_order.tsx
index 7fee8c4df..95a3671c4 100644
--- a/packages/website/ts/components/fill_order.tsx
+++ b/packages/website/ts/components/fill_order.tsx
@@ -205,7 +205,7 @@ export class FillOrder extends React.Component<FillOrderProps, FillOrderState> {
             amount: orderMakerAmount
                 .times(takerAssetToken.amount)
                 .div(orderTakerAmount)
-                .floor(),
+                .integerValue(BigNumber.ROUND_FLOOR),
             symbol: makerToken.symbol,
         };
         const fillAssetToken = {
@@ -219,7 +219,7 @@ export class FillOrder extends React.Component<FillOrderProps, FillOrderState> {
             const orderReceiveAmountBigNumber = orderMakerAmount
                 .times(this.props.orderFillAmount)
                 .dividedBy(orderTakerAmount)
-                .floor();
+                .integerValue(BigNumber.ROUND_FLOOR);
             orderReceiveAmount = this._formatCurrencyAmount(orderReceiveAmountBigNumber, makerToken.decimals);
         }
         const isUserMaker =
diff --git a/packages/website/ts/utils/utils.ts b/packages/website/ts/utils/utils.ts
index 890f1553a..e84f9d0cc 100644
--- a/packages/website/ts/utils/utils.ts
+++ b/packages/website/ts/utils/utils.ts
@@ -394,7 +394,7 @@ export const utils = {
     },
     getUsdValueFormattedAmount(amount: BigNumber, decimals: number, price: BigNumber): string {
         const unitAmount = Web3Wrapper.toUnitAmount(amount, decimals);
-        const value = unitAmount.mul(price);
+        const value = unitAmount.multipliedBy(price);
         return utils.format(value, constants.NUMERAL_USD_FORMAT);
     },
     openUrl(url: string): void {
diff --git a/yarn.lock b/yarn.lock
index 7e0046213..a7c126151 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3391,6 +3391,10 @@ bignumber.js@~4.1.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/bignumber.js/-/bignumber.js-4.1.0.tgz#db6f14067c140bd46624815a7916c92d9b6c24b1"
 
+bignumber.js@~8.0.2:
+  version "8.0.2"
+  resolved "https://registry.yarnpkg.com/bignumber.js/-/bignumber.js-8.0.2.tgz#d8c4e1874359573b1ef03011a2d861214aeef137"
+
 binary-extensions@^1.0.0:
   version "1.11.0"
   resolved "https://registry.yarnpkg.com/binary-extensions/-/binary-extensions-1.11.0.tgz#46aa1751fb6a2f93ee5e689bb1087d4b14c6c205"
@@ -4035,9 +4039,9 @@ chai-as-promised@^7.1.0, chai-as-promised@^7.1.1:
   dependencies:
     check-error "^1.0.2"
 
-chai-bignumber@^2.0.1, chai-bignumber@^2.0.2:
-  version "2.0.2"
-  resolved "https://registry.yarnpkg.com/chai-bignumber/-/chai-bignumber-2.0.2.tgz#de6c219c690b2d66b646ad6930096f9ba2199643"
+chai-bignumber@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/chai-bignumber/-/chai-bignumber-3.0.0.tgz#e90cf1f468355bbb11a9acd051222586cd2648a9"
 
 chai@^3.5.0:
   version "3.5.0"