Kalshi and Polymarket vs the books
Prediction market board
Puts exchange contract prices next to de-vigged sportsbook probabilities and flags where they disagree.
Built for real in
Statyx odds board, which blends Kalshi and Polymarket
Prediction market board
Demo dataExchange contract prices next to a de-vigged sportsbook fair probability. The gap is the potential edge before fees.
| Market | Kalshi | Polymarket | Book fair | Gap | Vol 24h | 24h · vs fair |
|---|---|---|---|---|---|---|
| 77¢bid 76¢ | 78¢bid 77¢ | 74.8% −297 · Pinnacle | −2.2pprich | $779K $22.3K at ask | ||
| 57¢bid 56¢ | 58¢bid 57¢ | 57.1% −133 · Pinnacle | +0.1ppfair | $78.9K $20.4K at ask | ||
| 52¢bid 50¢ | 53¢bid 51¢ | 54.2% −118 · Pinnacle | +2.2ppbuy | $458K $10.1K at ask | ||
| 63¢bid 62¢ | 63¢bid 62¢ | 59.8% −148 · Pinnacle | −3.2pprich | $825K $6.7K at ask | ||
| 56¢bid 55¢ | 55¢bid 54¢ | 57.1% −133 · Pinnacle | +2.1ppbuy | $340K $14.9K at ask | ||
| 51¢bid 49¢ | 48¢bid 47¢ | 45.8% +118 · Pinnacle | −2.2pprich | $687K $18.8K at ask | ||
| 56¢bid 55¢ | 57¢bid 56¢ | 54.2% −118 · Pinnacle | −1.8pprich | $387K $11.9K at ask | ||
| 20¢bid 18¢ | 18¢bid 16¢ | 23.0% +335 · FanDuel | +5.0ppbuy | $464K $9.2K at ask | ||
| 59¢bid 56¢ | 55¢bid 52¢ | 58.1% −138 · DraftKings | +3.1ppbuy | $1.5M $26.0K at ask | ||
| 81¢bid 77¢ | 83¢bid 79¢ | 78.9% −373 · BetMGM | −2.1pprich | $1.3M $26.2K at ask | ||
| 47¢bid 43¢ | 48¢bid 45¢ | 46.2% +116 · Caesars | −0.8pprich | $373K $29.7K at ask |
BUF to win the AFC
Conference winner · season future
- 1 · Contract → probability
Cheapest YES is Polymarket at 18¢. A YES contract pays $1.00 if it happens, so 18¢ implies 18.0%.
- 2 · Book → fair
FanDuel Yes +312 / No −435 imply 24.3% + 81.3% = 105.6% (5.6% hold). Removing the hold: 24.3% ÷ 105.6% = 23.0% fair (+335).
- 3 · Compare
Gap = 23.0% − 18.0% = +5.0ppbuy
The exchange is cheaper than the book's fair price. Buying YES has a potential edge of $0.050 per contract (+27.7% on 18¢ risked) before fees.
After a 1¢ fee the YES gap is +4.0pp, +21.0% expected return. Depth at the best ask: $9.2K ≈ 51,111 contracts before the price moves.
Honest note.Exchange fees, the bid/ask spread and thin depth often erase gaps under 2pp. Book fair is itself an estimate (one book, multiplicative de-vig), and exchange contracts settle on their own rules, which can differ from a sportsbook's. Prices here are simulated.
What you'd get for your product
- Contract prices beside book odds
- Probability gap per event
- Liquidity and volume context
- Alerts on new gaps
Built on your data feeds, in your repo and your accounts. Typical stack: Exchange APIs, Probability normalization.
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