Prediction markets and sportsbooks price the same outcomes — sometimes at meaningfully different prices. When the gap is real, you can hold opposing positions at the two venues and fix a profit regardless of outcome. This walkthrough is how, with worked numbers.
Why the prices diverge
A sportsbook's futures price on, say, the Chiefs to win the Super Bowl includes a vig margin and reflects mostly US betting flow. Polymarket's contract on the same outcome includes crypto-funded global flow, often institutional, and prices closer to true probability.
