diff --git a/packages/bignumber/src.ts/bignumber.ts b/packages/bignumber/src.ts/bignumber.ts
index 2955249d3c..8bf9197a35 100644
--- a/packages/bignumber/src.ts/bignumber.ts
+++ b/packages/bignumber/src.ts/bignumber.ts
@@ -202,7 +202,7 @@ export class BigNumber implements Hexable {
         if (value instanceof BigNumber) { return value; }
 
         if (typeof(value) === "string") {
-            if (value.match(/-?0x[0-9a-f]+/i)) {
+            if (value.match(/^-?0x[0-9a-f]+$/i)) {
                 return new BigNumber(_constructorGuard, toHex(value));
             }
 
diff --git a/packages/testcases/ingest.js b/packages/testcases/ingest.js
new file mode 100644
index 0000000000..5b9e4bc63a
--- /dev/null
+++ b/packages/testcases/ingest.js
@@ -0,0 +1,13 @@
+"use strict";
+
+const fs = require("fs");
+const { resolve } = require("path");
+
+const { saveTests } = require("./lib/index");
+
+function ingest(tag) {
+    const data = JSON.parse(fs.readFileSync(resolve(__dirname, "input", tag + ".json")).toString());
+    saveTests(tag, data);
+}
+
+ingest("bignumber")
diff --git a/packages/testcases/input/bignumber.json b/packages/testcases/input/bignumber.json
new file mode 100644
index 0000000000..f5f353373d
--- /dev/null
+++ b/packages/testcases/input/bignumber.json
@@ -0,0 +1,187 @@
+[
+  {
+    "testcase": "HexStrings - Zero; odd-length",
+    "value": "0x0",
+    "expectedValue": "0x00"
+  },
+  {
+    "testcase": "HexStrings - Zero; padded",
+    "value": "0x00",
+    "expectedValue": "0x00"
+  },
+  {
+    "testcase": "HexStrings - Negative Zero",
+    "value": "-0x00",
+    "expectedValue": "0x00"
+  },
+  {
+    "testcase": "HexStrings - One",
+    "value": "0x1",
+    "expectedValue": "0x01"
+  },
+  {
+    "testcase": "HexStrings - Negative One",
+    "value": "-0x1",
+    "expectedValue": "-0x01"
+  },
+  {
+    "testcase": "HexStrings - Over 32-bits",
+    "value": "0xdeadbeef1",
+    "expectedValue": "0x0deadbeef1"
+  },
+  {
+    "testcase": "HexStrings - Over 32-bits (negative)",
+    "value": "-0xdeadbeef1",
+    "expectedValue": "-0x0deadbeef1"
+  },
+  {
+    "testcase": "HexStrings - Over 53-bits",
+    "value": "0xfffffffffffffff",
+    "expectedValue": "0x0fffffffffffffff"
+  },
+  {
+    "testcase": "HexStrings - Over 53-bits (negative)",
+    "value": "-0xfffffffffffffff",
+    "expectedValue": "-0x0fffffffffffffff"
+  },
+  {
+    "testcase": "HexStrings - Over 64-bits",
+    "value": "0xdeadbeefdeadbeef1",
+    "expectedValue": "0x0deadbeefdeadbeef1"
+  },
+  {
+    "testcase": "HexStrings - Over 64-bits (negative)",
+    "value": "-0xdeadbeefdeadbeef1",
+    "expectedValue": "-0x0deadbeefdeadbeef1"
+  },
+  {
+    "testcase": "DecimalStrings - Zero",
+    "value": "0",
+    "expectedValue": "0x00"
+  },
+  {
+    "testcase": "DecimalStrings - One",
+    "value": "1",
+    "expectedValue": "0x01"
+  },
+  {
+    "testcase": "DecimalStrings - Negative One",
+    "value": "-1",
+    "expectedValue": "-0x01"
+  },
+  {
+    "testcase": "DecimalStrings - Life and such",
+    "value": "42",
+    "expectedValue": "0x2a"
+  },
+  {
+    "testcase": "DecimalStrings - Life and such (negative)",
+    "value": "-42",
+    "expectedValue": "-0x2a"
+  },
+  {
+    "testcase": "DecimalStrings - MAX_SAFE_INTEGER",
+    "value": "9007199254740991",
+    "expectedValue": "0x1fffffffffffff"
+  },
+  {
+    "testcase": "DecimalStrings - MAX_SAFE_INTEGER (negative)",
+    "value": "-9007199254740991",
+    "expectedValue": "-0x1fffffffffffff"
+  },
+  {
+    "testcase": "DecimalStrings - High value not on compact boundary",
+    "value": "9007199254740995",
+    "expectedValue": "0x20000000000003"
+  },
+  {
+    "testcase": "DecimalStrings - Low value not on compact boundary",
+    "value": "-9007199254740995",
+    "expectedValue": "-0x20000000000003"
+  },
+  {
+    "testcase": "Numbers - Zero",
+    "value": 0,
+    "expectedValue": "0x00"
+  },
+  {
+    "testcase": "Numbers - One",
+    "value": 1,
+    "expectedValue": "0x01"
+  },
+  {
+    "testcase": "Numbers - Negative One",
+    "value": -1,
+    "expectedValue": "-0x01"
+  },
+  {
+    "testcase": "Numbers - BigNumber Safe",
+    "value": 9007199254740990,
+    "expectedValue": "0x1ffffffffffffe"
+  },
+  {
+    "testcase": "Numbers - BigNumber Safe (negative)",
+    "value": -9007199254740990,
+    "expectedValue": "-0x1ffffffffffffe"
+  },
+  {
+    "testcase": "Invalid - Empty value",
+    "value": "0x",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - The x of 0x0",
+    "value": "x",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Negative at the end",
+    "value": "0123-",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Negative in middle",
+    "value": "0123-456",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Double negative",
+    "value": "--123",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - MAX_SAFE_INTEGER",
+    "value": 9007199254740991,
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - -MAX_SAFE_INTEGER",
+    "value": -9007199254740991,
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Too high; safe value",
+    "value": 9007199254740996,
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Too low; save value",
+    "value": -9007199254740996,
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Random text",
+    "value": "hello world",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - Bad hex character",
+    "value": "0x123g",
+    "expectedValue": null
+  },
+  {
+    "testcase": "Invalid - See #935",
+    "value": "0-0x1 whatever",
+    "expectedValue": null
+  }
+]
diff --git a/packages/testcases/src.ts/index.ts b/packages/testcases/src.ts/index.ts
index 2b1134d2dd..86e17f1ebf 100644
--- a/packages/testcases/src.ts/index.ts
+++ b/packages/testcases/src.ts/index.ts
@@ -8,6 +8,12 @@ import { randomBytes, randomHexString, randomNumber } from "./random";
 export { randomBytes, randomHexString, randomNumber };
 
 export module TestCase {
+    export type BigNumber = {
+        testcase: string;
+        value: string | number;
+        expectedValue: string;
+    };
+
     export type HDWalletNode = {
         path: string;
         address: string;
diff --git a/packages/testcases/testcases/bignumber.json.gz b/packages/testcases/testcases/bignumber.json.gz
new file mode 100644
index 0000000000..bc5a94ab93
Binary files /dev/null and b/packages/testcases/testcases/bignumber.json.gz differ
diff --git a/packages/tests/src.ts/test-utils.ts b/packages/tests/src.ts/test-utils.ts
index cc98750443..ef7c5ed3c1 100644
--- a/packages/tests/src.ts/test-utils.ts
+++ b/packages/tests/src.ts/test-utils.ts
@@ -441,26 +441,6 @@ describe('Test Bytes32String coder', function() {
     });
 });
 
-describe('Test BigNumber', function() {
-    it("computes absolute values", function() {
-        function testAbs(test: { expected: string, value: string }) {
-            let value = ethers.BigNumber.from(test.value);
-            let expected = ethers.BigNumber.from(test.expected);
-            assert.ok(value.abs().eq(expected), 'BigNumber.abs - ' + test.value);
-        }
-
-        [
-            { value: "0x0", expected: "0x0" },
-            { value: "-0x0", expected: "0x0" },
-            { value: "0x5", expected: "0x5" },
-            { value: "-0x5", expected: "0x5" },
-            { value: "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
-            { value: "-0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
-            { value: "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
-            { value: "-0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
-        ].forEach(testAbs);
-    });
-});
 
 function getHex(value: string): string {
     return "0x" + Buffer.from(value).toString("hex");
@@ -537,3 +517,47 @@ describe("Test Signature Manipulation", function() {
         });
     });
 });
+
+describe("BigNumber", function() {
+    const tests: Array<TestCase.BigNumber> = loadTests("bignumber");
+    tests.forEach((test) => {
+        if (test.expectedValue == null) {
+            it(test.testcase, function() {
+                assert.throws(() => {
+                    const value = ethers.BigNumber.from(test.value);
+                    console.log("ERROR", value);
+                }, (error: Error) => {
+                    return true;
+                });
+            });
+        } else {
+            it(test.testcase, function() {
+                const value = ethers.BigNumber.from(test.value);
+                assert.equal(value.toHexString(), test.expectedValue);
+
+                const value2 = ethers.BigNumber.from(value)
+                assert.equal(value2.toHexString(), test.expectedValue);
+            });
+        }
+    });
+
+    [
+        { value: "0x0", expected: "0x0" },
+        { value: "-0x0", expected: "0x0" },
+        { value: "0x5", expected: "0x5" },
+        { value: "-0x5", expected: "0x5" },
+        { value: "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
+        { value: "-0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
+        { value: "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
+        { value: "-0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", expected: "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" },
+    ].forEach((test) => {
+        it(`absolute value (${ test.value })`, function() {
+            const value = ethers.BigNumber.from(test.value);
+            const expected = ethers.BigNumber.from(test.expected);
+            assert.ok(value.abs().eq(expected));
+        });
+    });
+
+    // @TODO: Add more tests here
+
+});