Polymarket fees: trading, gas, and the real cost of a position
Published 2026-05-17 · Last reviewed 2026-05-17
TL;DR
- Polymarket charges 0% trading fees on both makers and takers.
- You pay Polygon gas (usually <$1) on funding, withdrawing, and approving USDC.
- The biggest real cost is the on-ramp: card-to-USDC services charge 1–4% to get dollars onto Polygon in the first place.
Polymarket says "zero trading fees" on the box. The actual bill is a little more honest than that.
What a Polymarket round-trip really costs
Imagine funding $100 from a debit card and buying 200 contracts at 50¢. The math:
- Card → USDC on Polygon — $2–4 on-ramp fee (1–4% depending on provider)
- USDC approval (one-time per market) — ~$0.05 in gas
- Buy 200 contracts at $0.50 — $0.00 trading fee, ~$0.10 gas
- Sell or settle — $0.00 trading fee, ~$0.10 gas
- USDC → bank — $1–3 off-ramp fee (1–3%)
Total friction on a $100 round-trip: roughly $3–7. That's the real number to compare against Kalshi's ~$3–7 per round-trip in trading fees on the same size.
Where Polymarket wins on cost
If your USDC already lives on Polygon — from a previous trade, an on-chain payroll, or cross-chain bridging — the on-ramp cost goes to zero. Trading from existing USDC, Polymarket is essentially free.
Where Kalshi wins on cost
US users who fund once via ACH (free) and trade contracts priced far from 50¢ can run very cheaply on Kalshi. The Kalshi fee formula caps near-the-money but stays meaningful in the middle of the range.
Practical takeaway
Choose based on workflow, not headline fees. Active crypto-native traders should use Polymarket. US users who want USD in and USD out should use Kalshi.
Frequently asked questions
Does Polymarket really charge nothing to trade?
Yes. The order book and AMM both execute at 0% fees. Polymarket's revenue comes from spreads, market-making, and adjacent services rather than per-trade commissions.
What are the actual costs then?
Three: (1) Polygon gas on each on-chain action — typically cents; (2) on-ramp fees of 1–4% to convert fiat to USDC; (3) the spread between bid and ask on illiquid markets.
Is Polymarket cheaper than Kalshi?
For active small-position trading, often yes. For a single large deposit held in cash and traded once or twice, Kalshi can be cheaper because ACH funding is free.
Are there withdrawal fees?
Polymarket itself charges no withdrawal fee. You pay Polygon gas to move USDC out, plus an off-ramp fee (1–3%) if you convert USDC back to fiat via a service like MoonPay or a centralized exchange.
Are there hidden costs in resolution?
No. Markets settle at $1 or $0 with no platform skim. The only resolution-related cost is the rare gas spent claiming winnings if the UI doesn't auto-redeem.
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