diff --git a/package.json b/package.json
index 43859d0..e5cf598 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@polymarket/sdk",
-  "version": "5.0.1",
+  "version": "5.0.2",
   "description": "SDK to simplify common interactions with the Polymarket proxy wallet",
   "author": "Tom French <tom@tomfren.ch>",
   "repository": "https://github.com/TokenUnion/polymarket-sdk.git",
diff --git a/src/index.ts b/src/index.ts
index e00597c..833525d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3,6 +3,6 @@ export * from "./matic";
 export * from "./markets";
 export * from "./debt";
 
-export { ethTransferTransaction, erc20TransferTransaction, getIndexSet } from "./utils";
+export { ethTransferTransaction, erc20TransferTransaction, getIndexSet, getMarketIndex } from "./utils";
 export { getProxyWalletAddress } from "./proxyWallet";
 export { negRiskOperations } from "./negRisk";
diff --git a/src/utils/getIndexSet.ts b/src/utils/getIndexSet.ts
index cdd712f..ed144a8 100644
--- a/src/utils/getIndexSet.ts
+++ b/src/utils/getIndexSet.ts
@@ -1,3 +1,8 @@
+/**
+ * Gets the index set corresponding to an array of market indices.
+ * @param indices An array of market indices.
+ * @returns The corresponding index set.
+ */
 const getIndexSet = (indices: number[]) =>
   // eslint-disable-next-line no-bitwise
   [...new Set(indices)].reduce((acc, index) => acc + (1 << index), 0);
diff --git a/src/utils/getMarketIndex.ts b/src/utils/getMarketIndex.ts
new file mode 100644
index 0000000..d4c9a8e
--- /dev/null
+++ b/src/utils/getMarketIndex.ts
@@ -0,0 +1,10 @@
+/**
+ * Gets the index of a neg-risk market index from the questionId.
+ * @remarks
+ * The last byte of the questionId contains the index of the neg-risk market.
+ * @param questionId The questionId of the neg-risk market.
+ * @returns The index of the neg-risk market.
+ */
+const getMarketIndex = (questionId: string): number => parseInt(questionId.slice(-2), 16);
+
+export { getMarketIndex };
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 8af3d20..bbb5333 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -3,3 +3,4 @@ export { erc1155ApprovalTransaction } from "./approveErc1155";
 export { erc20TransferTransaction } from "./transferErc20";
 export { ethTransferTransaction } from "./transferEth";
 export { getIndexSet } from "./getIndexSet";
+export { getMarketIndex } from "./getMarketIndex";
diff --git a/test/getIndexSet.test.ts b/test/getIndexSet.test.ts
index 18e37e9..bbc56c0 100644
--- a/test/getIndexSet.test.ts
+++ b/test/getIndexSet.test.ts
@@ -22,7 +22,7 @@ const testCases = [
 ] as [number[], number][];
 
 describe("getIndexSet", () => {
-  it.each(testCases)(`should compute the index set`, (indices, expectedIndexSet) => {
+  it.each(testCases)(`should get the index set`, (indices, expectedIndexSet) => {
     expect(getIndexSet(indices)).toEqual(expectedIndexSet);
   });
 });
diff --git a/test/getMarketIndex.test.ts b/test/getMarketIndex.test.ts
new file mode 100644
index 0000000..7875fe2
--- /dev/null
+++ b/test/getMarketIndex.test.ts
@@ -0,0 +1,18 @@
+/* eslint-env jest */
+
+import { getMarketIndex } from "../src";
+
+const testCases: [string, number][] = [
+  ["0xb20c874543db3de05e85f24dc912e915a641c579db553ff12ed135a68b3f7500", 0],
+  ["0xb20c874543db3de05e85f24dc912e915a641c579db553ff12ed135a68b3f7501", 1],
+  ["0xb20c874543db3de05e85f24dc912e915a641c579db553ff12ed135a68b3f7510", 16],
+  ["0x1d2daa077aa4441be685c80a2ffac5c962eebf791ee72b8d178bfaf305847c11", 17],
+  ["0x1d2daa077aa4441be685c80a2ffac5c962eebf791ee72b8d178bfaf305847cFF", 255],
+  ["0x1d2daa077aa4441be685c80a2ffac5c962eebf791ee72b8d178bfaf305847c0A", 10],
+];
+
+describe("getMarketIndex", () => {
+  it.each(testCases)(`should get the market index`, (questionId, expectedMarketIndex) => {
+    expect(getMarketIndex(questionId)).toEqual(expectedMarketIndex);
+  });
+});