KalshiKalshi arbitrage: fees, rules and live spreads
Kalshi is a US exchange regulated by the CFTC, so its contracts, account rules and fees work differently from crypto venues. Those differences are exactly where spreads open up, and where they can turn against you.
Kalshi in the latest scan
Top Kalshi spreads right now
High-confidence matches with real depth, sorted by quality. Prices link to each venue; read both markets' rules before trading.
| Event | Buy YES | Buy NO | ROI | Ends | Profit on $1,000 |
|---|---|---|---|---|---|
| "Wild Horse Nine" Rotten Tomatoes Score? — 92+Movies | KS 52.0¢ | PM 29.0¢ | 20.85% | 15d | $8.80 |
| "The Hunger Games: Sunrise on the Reaping" Rotten Tomatoes Score? — 60+Movies | KS 84.0¢ | PM 12.0¢ | 3.16% | 29d | $26.27 |
| "Avengers: Doomsday" Rotten Tomatoes Score? — 80+Movies | KS 68.0¢ | PM 26.0¢ | 4.69% | 57d | $10.89 |
| The Game Awards: Best Independent Game — MewgenicsGames | KS 9.0¢ | PM 88.0¢ | 2.49% | 2mo | $5.69 |
| Avengers: Doomsday: Rotten Tomatoes score — Above 70Entertainment | KS 80.0¢ | PF 17.0¢ | 1.56% | 57d | $15.64 |
| NBA: 2026-27 Coach of the Year — Micah NoriNBA | KS 7.0¢ | PM 87.2¢ | 5.65% | 9mo | $6.41 |
| NBA: 2026-27 Coach of the Year — Tyronn LueNBA | KS 2.0¢ | PM 94.4¢ | 3.59% | 9mo | $12.31 |
| Democratic Presidential Nominee 2028 — Alexandria Ocasio-CortezUnited States | KS 14.0¢ | PM 82.9¢ | 2.31% | 24mo | $23.09 |
How Kalshi works
Kalshi lists event contracts that pay $1 if the event happens. You can buy YES or NO directly; each has its own order book. Prices are in cents, and a contract's rules spell out the exact source, time and threshold that decide it.
Because Kalshi is a regulated exchange, its contracts are often written more precisely than crypto equivalents: "above 4.25%" at a named release, or a game result "including overtime". That precision is useful, but it means a Kalshi contract and a similar-looking Polymarket market can resolve differently.
The Kalshi fee, worked out
Kalshi's taker fee is 0.07 × number of contracts × price × (1 − price), rounded up to the next cent per order. At 50¢ that is 1.75¢ per contract; at 10¢ or 90¢ it falls to 0.63¢. Fees are largest exactly where spreads are most common, in the middle of the price range.
ArbSonar applies this formula to the Kalshi leg at the quoted price. Rounding is per order, so many small orders cost slightly more than one large one; leave a cent of margin on thin spreads.
Where Kalshi spreads come from
Kalshi and Polymarket often price the same sports, economics and politics events a few cents apart because their users differ: dollar accounts on one side, crypto wallets on the other, and little capital moves between them. Predict.fun also links some markets to their Kalshi ticker, which gives exact pairs.
Most Kalshi-Polymarket spreads are small, around 1–3% before you account for the time your money is locked. The APR column helps compare a 2% spread that resolves tomorrow with one that resolves next year.
Spreads by partner venue
289 spreads with Polymarket
36 spreads with Predict.fun
11 spreads with LimitlessKalshi questions
How much are Kalshi fees?
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The taker fee is about 0.07 × contracts × P × (1 − P), rounded up to the next cent per order. At a 50¢ price that is 1.75¢ per contract. Some markets also charge makers. ArbSonar includes the taker fee in every Kalshi leg.
Is Kalshi regulated?
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Yes. Kalshi is a designated contract market regulated by the US Commodity Futures Trading Commission. Accounts are in US dollars and require identity verification.
Is Kalshi vs Polymarket arbitrage risk-free?
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Only if both contracts resolve the same way. Kalshi rules are often stricter about sources and timing, so read both rule sets. Also check depth: the profit is capped by the size quoted on both books.
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