Polymarket's fee schedule is short: a 2% fee on the notional value of every trade you execute, and nothing else that shows up as a separate line item. No monthly fee, no fee to open an account, no fee to hold a position while a market runs its course. If you've seen Polymarket described as "free to trade" somewhere, that's roughly true for everything except the one fee that actually applies — and knowing exactly when that 2% hits, and what it does to your numbers, matters more than the headline rate suggests.
This is a full breakdown of every cost you'll actually see using Polymarket — the trading fee, deposits, withdrawals, and the gas costs that trip up people who assume a blockchain-based exchange must be expensive to use. If you're weighing Polymarket's costs directly against Kalshi's, see our side-by-side comparison — this article is a deep dive into Polymarket on its own.
The only fee that matters: 2% on notional
Polymarket charges a 2% fee on the notional value of a filled trade — not on your profit, and not on the payout when a contract resolves. Buy $100 of YES shares at 50 cents, and the fee is $2, charged at the moment the order fills. There's no second charge when the contract settles and pays out; the 2% you pay at execution is the entire cost of that trade.
Because it's a flat percentage of notional rather than a cut of profit, the fee is identical whether the trade turns out to be a winner or a loser. A losing position doesn't get a fee refund, and a winning one isn't charged again at settlement.
No maker fee — and no maker rebate
Polymarket doesn't run a maker/taker schedule the way some exchanges do to encourage liquidity provision. There's no separate maker fee, but there's also no rebate for posting a resting limit order that adds depth to the book. Whether you cross the spread with a market order or sit in the order book waiting to be filled, the 2% applies the same way once your order executes. That's simpler to model than a tiered maker/taker fee, but it also means there's no cost advantage to being the patient side of the trade the way there sometimes is on exchanges that pay liquidity providers.
Why there's no separate gas fee to trade
Polymarket runs on Polygon rather than Ethereum mainnet, and it settles the actions you actually take — placing an order, cancelling one — through infrastructure that covers the on-chain gas cost on your behalf. In practice, that means you don't see a separate gas charge attached to every order the way you would interacting directly with a typical on-chain exchange. This is one of the more common misconceptions about trading on a blockchain-based platform: people assume "on-chain" means "you pay gas for everything," and for Polymarket's day-to-day order flow, that isn't how it works.
Deposits and withdrawals: what actually costs money
Polymarket is non-custodial and settles in USDC on Polygon, so funding your account means getting USDC into a wallet connected to Polymarket — typically by buying USDC on an exchange like Coinbase and sending it to a Polygon address. Polymarket itself doesn't charge a platform fee to deposit, and the minimum to get started is roughly $50. The cost you'll actually pay comes from outside Polymarket: whatever your exchange charges to buy USDC, plus the small Polygon network gas fee to move it — negligible next to what the equivalent transfer costs on Ethereum mainnet.
Withdrawing works the same way in reverse. Polymarket doesn't layer a separate platform fee onto withdrawals — the cost is Polygon gas to move USDC out, plus whatever your exchange charges to convert USDC back into cash if that's the end goal. That's a structurally different model from platforms that charge a specific cut for taking your own money off the platform.
What losing trades and settlement actually cost
Nothing beyond the 2% you already paid to open the position. Polymarket doesn't charge anything additional when a market resolves, whichever way it resolves — settlement itself is free. Your entire cost on any single trade is the fee you paid when the order filled; there's no second charge waiting for you at the end, and no discount either if the position loses.
Polymarket vs Kalshi: two different fee shapes
Kalshi's fee model looks structurally different: it charges roughly 7% of the profit on a winning trade rather than a flat percentage of notional, and losing legs aren't charged at all. Polymarket's 2% on notional is simpler to estimate up front — you know the cost the moment you place the order, regardless of outcome — while Kalshi's fee only ever applies to money you've actually made. Neither shape is strictly cheaper; which one costs you more depends on your win rate and position size. For the full breakdown, including how each fee structure interacts with liquidity and market coverage, see our Kalshi vs Polymarket fees and liquidity comparison.
What this means if you're calculating an arbitrage edge
If you're buying YES on one platform and NO on the other for the same event, both fees come out of your gross spread before you see a real number. A gross spread that looks attractive before fees can shrink fast once Polymarket's 2% taker fee and Kalshi's fee on the winning leg are both subtracted — which is why net edges worth acting on tend to be measured in fractions of a percent to a few percent, not the headline spread you see before fees. Net edges on live Kalshi/Polymarket pairs run well under 1% per position at the median, with wider spreads showing up during high-activity events; see /proof for the current numbers. Our free arbitrage calculator lets you plug in both sides' prices and see the net edge after fees before you commit anything.
Quick reference: what you'll actually pay
- Trading: 2% of notional per filled order, charged once at execution
- Maker vs taker: no difference — same 2% either way, no rebate for resting orders
- Gas: not a separate charge for day-to-day trading, since Polymarket covers it on Polygon
- Deposits: no platform fee; roughly $50 minimum; your exchange's USDC purchase cost applies
- Withdrawals: no platform fee; Polygon gas plus your exchange's conversion cost
- Settlement: free, whether the position wins or loses
Arbitrage Agent calculates the net edge automatically for every matched Polymarket/Kalshi pair it tracks — you see the number after both platforms' fees, not the gross spread that fees would otherwise eat into. See the plans, starting at $29/month for dry-run tracking of live detected spreads, or join the waitlist for early access.
Related articles
- Kalshi vs Polymarket: Fees, Liquidity & Which Is Better for Arbitrage (2026)
- The Polymarket API Explained: CLOB, WebSockets and Order Placement (2026)
- Prediction Market Arbitrage Taxes 2026: What You Owe and How to Report It
- How Much Can You Make with Prediction Market Arbitrage?
Key terms: Spread · Resolution Risk · CLOB (Central Limit Order Book)