diff --git a/extension/changelog.json b/extension/changelog.json
index 825919c65..453c40803 100644
--- a/extension/changelog.json
+++ b/extension/changelog.json
@@ -4,7 +4,10 @@
 		"title": "Beta",
 		"date": false,
 		"logs": {
-			"features": [{ "message": "Sidebar timer for OC 2.", "contributor": "DeKleineKobini" }],
+			"features": [
+				{ "message": "Sidebar timer for OC 2.", "contributor": "DeKleineKobini" },
+				{ "message": "Fill Max for Item Market 2.0.", "contributor": "TheFoxMan" }
+			],
 			"fixes": [],
 			"changes": [
 				{ "message": "Disable OC1 timer when detecting OC 2 data.", "contributor": "DeKleineKobini" },
diff --git a/extension/manifest.json b/extension/manifest.json
index 7075bb709..85c6a9e89 100644
--- a/extension/manifest.json
+++ b/extension/manifest.json
@@ -430,11 +430,16 @@
 		},
 		{
 			"matches": ["https://www.torn.com/page.php?sid=ItemMarket*"],
-			"css": ["scripts/features/drug-details/ttDrugDetails.css", "scripts/features/highlight-cheap-items/ttHighlightCheapItems.css"],
+			"css": [
+				"scripts/features/drug-details/ttDrugDetails.css",
+				"scripts/features/highlight-cheap-items/ttHighlightCheapItems.css",
+				"scripts/features/item-market-fill-max/ttItemMarketFillMax.css"
+			],
 			"js": [
 				"scripts/content/itemmarket/ttItemMarket.js",
 				"scripts/features/drug-details/ttDrugDetails.js",
-				"scripts/features/highlight-cheap-items/ttHighlightCheapItems.js"
+				"scripts/features/highlight-cheap-items/ttHighlightCheapItems.js",
+				"scripts/features/item-market-fill-max/ttItemMarketFillMax.js"
 			],
 			"run_at": "document_end"
 		},
diff --git a/extension/pages/settings/settings.html b/extension/pages/settings/settings.html
index bdf47d6f0..3c224837a 100644
--- a/extension/pages/settings/settings.html
+++ b/extension/pages/settings/settings.html
@@ -1604,6 +1604,10 @@ <h2>
 							<input id="itemmarket-leftBar" type="checkbox" />
 							<label for="itemmarket-leftBar">Move the market bar to the left.</label>
 						</div>
+						<div class="option">
+							<input id="itemmarket-fillMax" type="checkbox" />
+							<label for="itemmarket-fillMax">Show fill max button to fill input box with maximum purchasable quantity.</label>
+						</div>
 					</section>
 					<section name="bounties">
 						<div class="header">Bounties</div>
diff --git a/extension/scripts/features/item-market-fill-max/ttItemMarketFillMax.css b/extension/scripts/features/item-market-fill-max/ttItemMarketFillMax.css
new file mode 100644
index 000000000..e87faa67c
--- /dev/null
+++ b/extension/scripts/features/item-market-fill-max/ttItemMarketFillMax.css
@@ -0,0 +1,19 @@
+.tt-show-fill-max [class*="rowWrapper__"] [class*="available__"] {
+	align-items: flex-start;
+	padding-top: 5px;
+}
+
+.tt-show-fill-max [class*="rowWrapper__"] [class*="available__"]::after {
+	content: "Fill Max";
+	position: absolute;
+	top: 20px;
+	color: var(--tt-color-green);
+	cursor: pointer;
+	width: calc(100px - 2 * 7px);
+	text-align: right;
+}
+
+body:not(.tt-mobile):not(.tt-tablet) .tt-show-fill-max [class*="rowWrapper__"] [class*="available__"]:hover::after {
+	color: #fff;
+	background-color: var(--tt-color-green);
+}
diff --git a/extension/scripts/features/item-market-fill-max/ttItemMarketFillMax.js b/extension/scripts/features/item-market-fill-max/ttItemMarketFillMax.js
new file mode 100644
index 000000000..e11957603
--- /dev/null
+++ b/extension/scripts/features/item-market-fill-max/ttItemMarketFillMax.js
@@ -0,0 +1,49 @@
+"use strict";
+
+(async () => {
+	const { mobile, tablet } = await checkDevice();
+
+	const feature = featureManager.registerFeature(
+		"Item Market Fill Max",
+		"item market",
+		() => settings.pages.itemmarket.fillMax,
+		addListener,
+		addButton,
+		removeButton,
+		{ storage: ["settings.pages.itemmarket.fillMax"] },
+		() => {
+			if (!hasAPIData()) return "No API access.";
+		}
+	);
+
+	function addListener() {
+		document.addEventListener("click", (event) => {
+			if (!event.target.matches("[class*='rowWrapper__'] [class*='available__']")) return;
+
+			if (!feature.enabled()) return;
+
+			const listing = event.target.closest("li");
+			// The purchase amount input is not visible in mobiles and tablets until
+			// the Buy icon is clicked. Hence exit early.
+			if ((mobile || tablet) && !listing.children[0].matches("[class*='sellerRow__'][class*='expanded__']")) return;
+
+			const quantityAvailable = listing.find("[class*='available__']").textContent.getNumber();
+			const moneyOnHand = document.find("#user-money").dataset.money.getNumber();
+			const itemPrice = listing.find("[class*='price__']").textContent.getNumber();
+			const purchasableQuantity = Math.min(quantityAvailable, Math.floor(moneyOnHand / itemPrice));
+
+			const quantityInput = listing.find(".input-money-group input:not([type])");
+			updateReactInput(quantityInput, purchasableQuantity);
+		});
+	}
+
+	async function addButton() {
+		const itemMarketRoot = await requireElement("#item-market-root");
+
+		itemMarketRoot.classList.add("tt-show-fill-max");
+	}
+
+	function removeButton() {
+		document.findAll(".tt-show-fill-max").forEach((x) => x.classList.remove("tt-show-fill-max"));
+	}
+})();
diff --git a/extension/scripts/global/globalData.js b/extension/scripts/global/globalData.js
index 518a0a2b9..0f538dd1c 100644
--- a/extension/scripts/global/globalData.js
+++ b/extension/scripts/global/globalData.js
@@ -661,6 +661,7 @@ const DEFAULT_STORAGE = {
 			itemmarket: {
 				highlightCheapItems: new DefaultSetting({ type: "number|empty", defaultValue: "" }),
 				leftBar: new DefaultSetting({ type: "boolean", defaultValue: false }),
+				fillMax: new DefaultSetting({ type: "boolean", defaultValue: true }),
 			},
 			competition: {
 				filter: new DefaultSetting({ type: "boolean", defaultValue: true }),