Kalshi and Polymarket both let you trade YES/NO contracts that pay $1.00 if you're right. The big differences are regulation, who can use them and how you fund your account — and for most people, where they live decides the question before anything else.
Polymarket vs Kalshi at a glance
| Factor | Polymarket (international) | Polymarket US | Kalshi |
|---|---|---|---|
| Regulation | Not registered in the US | CFTC-designated contract market (QCX LLC) | CFTC-designated contract market |
| Who can use it | Countries not on its restricted list | US residents in supported states | US residents; check Kalshi for other countries |
| Account currency | pUSD, funded with crypto | US dollars | US dollars |
| Payout per winning contract | $1.00 | $1.00 | $1.00 |
| Taker fee | shares × 0.04-0.07 × p × (1 − p) | US fee schedule | 0.07 × contracts × P × (1 − P), rounded up |
| Makers | No fee, 15-25% rebate | US fee schedule | Maker fee on some markets |
| KYC | Per its terms | Required | Required |
Regulation
Kalshi is a CFTC-designated contract market, fully regulated in the US and requiring identity checks for every account.
Polymarket has two products. The international site isn't registered in the US, and after the 2022 CFTC order it blocks new trades from US users. Polymarket US, run by QCX LLC, is a CFTC-designated contract market like Kalshi.
So in the US the comparison is really Kalshi vs Polymarket US: two regulated exchanges.
Fees compared
Both platforms use a formula that is highest at 50¢ and falls towards the extremes.
- Kalshi: taker fee = round up(0.07 × contracts × P × (1 − P)) according to its fee schedule. Some markets also charge makers 0.0175 × contracts × P × (1 − P).
- Polymarket (international): taker fee = shares × rate × p × (1 − p), with rates of 0.04-0.07 by category (fee docs). Makers pay nothing and earn rebates. Geopolitics is free.
Worked example — 100 contracts at 50¢, as a taker:
| Platform | Calculation | Fee |
|---|---|---|
| Kalshi | 0.07 × 100 × 0.5 × 0.5 | $1.75 |
| Polymarket, politics | 0.04 × 100 × 0.5 × 0.5 | $1.00 |
| Polymarket, sports | 0.05 × 100 × 0.5 × 0.5 | $1.25 |
| Polymarket, crypto | 0.07 × 100 × 0.5 × 0.5 | $1.75 |
Polymarket US has its own schedule, so compare the order ticket there directly with Kalshi's. Fees change: check both platforms before trading. More in Polymarket fees.
Payouts and contract structure
On both, a winning contract pays $1.00 and a losing one $0. Buying at 55¢ and winning makes 45¢ per contract before fees. Prices move from 1¢ to 99¢ and read as an implied probability.
Resolution differs: Polymarket's international markets resolve through the UMA optimistic oracle; Kalshi resolves under its own exchange rules and the sources written into each contract.
Markets
Both list politics, economics, sports, crypto, weather and culture. Polymarket's international site is known for a very wide range of global and current-events markets. Kalshi's contracts are each certified with the CFTC, so its list follows US rules — as does Polymarket US's.
Funding and withdrawals
- Kalshi: dollar funding through US payment methods such as bank transfer and cards; some crypto funding options.
- Polymarket US: US payment methods.
- Polymarket international: crypto bridged from many networks into pUSD, with no Polymarket deposit or withdrawal fees. See how to deposit.
Which should you choose?
- Where do you live? In the US: Kalshi or Polymarket US. Outside the US: check whether Polymarket is available in your country, and whether Kalshi serves it.
- Which markets do you want? Compare the specific events on each.
- Liquidity. Deep books mean fills closer to the price you see.
- Fees for your style. Frequent takers feel fees most; patient makers can avoid them on Polymarket.
Whichever you pick, every position can go to zero. Size trades with Kelly position sizing.
Related guides
Next step
In the United States, the regulated route is the Polymarket US app. Read our guides on signing up and depositing to get started, start small and only use money you can afford to lose.