Enter the two opposite outcomes from any two venues. We tell you whether the prices cross, the exact stake split, and the P&L if both legs fill at the prices you entered. Either leg can be a sportsbook line or a Polymarket / Kalshi price. Note that genuinely executable crossings are rare: in our own capture they existed in 0.36–0.39% of snapshots, with a negative median edge once both spreads were crossed.
Stakes are sized so the payout is identical whichever outcome hits. Round to the nearest dollar/share when you actually place — and place the leg that can move first.
An arbitrage exists when the implied probabilities of the two opposite outcomes add up to less than 100%. Inside one sportsbook that almost never happens — the vig guarantees it. It shows up between venues that disagree, and the biggest disagreements right now are between sportsbooks and prediction markets, because they have different crowds, fees, and liquidity.
Hunting arbs by hand is slow. ZenHodl's Edge Finder watches Polymarket, Kalshi and sportsbooks side by side against one calibrated fair value. Our per-sport CLV scorecard publishes the observed result—including negative values—without claiming that this one measure proves an edge.
One weekly email with live results, one model insight, and product updates.
Tuesday mornings. No spam.
Free tools for sharper betting and prediction-market trading.