Cross-Market Arbitrage
Buy YES on one venue and NO on another when the same event is mispriced across Kalshi, Polymarket, or Opinion. If combined cost is under $1.00, one side pays $1.00 at settlement. You do not need to forecast the outcome.
Delayed sample
Scanner demo
Cross-venue spreads on the same event across Kalshi, Polymarket, and Opinion.
Try unchecking "Show arbitrage only"
How it works
Buy both sides under $1.00. You do not need a forecast.
Find a price gap
The same event is priced differently on Kalshi, Polymarket, or Opinion.
Buy both sides under $1.00
Buy YES on the cheaper venue and NO on the other so combined cost stays under $1.00.
Collect $1.00 at settlement
One side always pays $1.00 at settlement, regardless of which outcome wins.
Example trade
- YES @ Kalshi
- 45¢
- NO @ Polymarket
- 48¢
- Total cost
- 93¢
- Settlement payout
- $1.00
- Gross edge
- 7¢ (~7.5% ROI)
Before Kalshi fees and fill risk. Net ROI after fees typically lands in the 1–8% range depending on contract price and size.
Vs sportsbook arbitrage
Sportsbooks often limit or ban accounts that keep winning with surebets. Prediction markets are exchanges. Different audiences (U.S. retail on Kalshi, global crypto-native traders on Polymarket) price the same question differently, and they generally do not limit or ban accounts for capturing those gaps.
| Factor | Sports betting arb | Prediction markets |
|---|---|---|
| Account limits / bans | Common for winners | Rare for winners |
| Typical ROI | 1–3% | 1–8% after fees |
| Why prices differ | Sharps correct books fast | Fragmented user bases, slower correction |
| Best venues | Pinnacle, Bet365, US books | Polymarket, Kalshi, Opinion |
Live scanner
Live plans refresh Kalshi, Polymarket, and Opinion spreads continuously, with fee-aware sizing, alerts, and API access.
Methodology: Prediction Market Arbitrage Report 2026