Kalshi is the US exchange that's been regulated since 2020, trades in dollars on web and mobile, and leads on sports and parlays. Polymarket is the world's biggest prediction market, deepest on politics and world events, cheaper on most non-sports fees, and in the US as a separate regulated product (polymarket.us, web and app) since December 2025. For sports and combos in the US, Kalshi. For politics, geopolitics and macro, Polymarket. For both, both.
Side by side
| Kalshi | Polymarket | |
|---|---|---|
| US regulation | CFTC DCM since Nov 2020 | US app on a CFTC DCM (QCX LLC) since Dec 2025; global site blocks US |
| Currency | US dollars | US dollars (US app); USDC stablecoin (global) |
| Platform | Web + iOS + Android | US: web + iOS + Android (polymarket.us); global: web + app |
| Identity checks | Details + SSN, ID if asked | US app: ID, selfie, SSN, proof of address |
| Minimum deposit | $10 ($1,000 wire) | $20 (US app) |
| Funding | Card, ACH, PayPal, Venmo, Cash App, crypto, wire | US: Apple/Google Pay, card, bank, wire · Global: USDC |
| Withdrawal speed | Card often instant; ACH days | US: ~3–4 business days; global: minutes on-chain |
| Taker fee | 7% × P × (1−P), all markets | Politics/finance/tech 4%, sports/econ 5%, crypto 7%, geopolitics 0% |
| Maker fee | Free on most markets | Free, plus rebates |
| Parlays | Combos, 30+ legs, since Sept 2025 | Combos, up to 10 legs, beta since Aug 2026 |
| Strongest markets | US sports, economics, combos | Politics, geopolitics, world events |
| Resolution | Exchange rules filed with CFTC | US: exchange rules · Global: UMA oracle |
| Minimum age | 18 | 18 |
Fees on a real trade
Say you buy 100 Yes contracts at 50¢ with a market order, the most expensive price point on both.
| Market type | Kalshi | Polymarket |
|---|---|---|
| Politics | $1.75 | $1.00 |
| Sports | $1.75 | $1.25 |
| Economics | $1.75 | $1.25 |
| Crypto | $1.75 | $1.75 |
| Geopolitics | $1.75 | $0 |
On a $50 stake these are 2–3.5%: real but small, and avoidable on both by posting limit orders, which are free. Fees decide very little unless you trade in and out constantly; liquidity and availability decide more.
Liquidity
Polymarket's global site is where the world prices elections, wars and central banks; the depth on a major political market is unmatched and spreads are a cent. Kalshi's depth is in US sports, where it moves billions a week in singles and combos, and in economic data releases. On a niche market either can be thin. The practical rule: trade each where the crowd is.
Legality
Both are in the same legal position on sports: federally regulated exchanges that a dozen states say are running unlicensed sportsbooks. Appeals courts have split (Third Circuit for the exchanges in April 2026; Ninth Circuit for Nevada in August 2026) and the Supreme Court has been asked to decide. Kalshi has pulled sports in Nevada, Michigan and Washington; Polymarket is blocked in Nevada and restricts sports in several states. Non-sports markets are mostly untouched on both. Details: Is Kalshi gambling? and Is Polymarket legal in the US?.
Experience
- Kalshi feels like a brokerage: web app, order book, charts, dollars in and out through familiar rails, interest paid on idle cash. Five years of operating history.
- Polymarket global feels like crypto: wallet, USDC, instant settlement, a decentralised oracle that occasionally produces a resolution people argue about.
- Polymarket US is the youngest product: heavier verification, narrower catalogue, improving monthly.
Verdict
- US sports and parlays: Kalshi. More legs, more liquidity, more states.
- Politics, geopolitics, world events: Polymarket. Deeper and cheaper, free on geopolitics.
- Economics and macro: either; Kalshi slightly more convenient for dollar traders, Polymarket slightly cheaper.
- Crypto markets: same fee; pick by liquidity on the specific market.
- Simplicity: Kalshi, unless you already live in crypto.
Outside the US and want Polymarket? Our referral link, no code needed.
Sign up on PolymarketOur 70¢ on "Kalshi over Polymarket for a US sports trader" reflects that the gap is real but shrinking: Polymarket's combos are three months old, and its state restrictions track Kalshi's within weeks.