How Prediction Markets Turn Crowd Belief Into Probability

Prediction markets let people trade contracts on real-world outcomes — where price equals probability. Unlike polls or expert opinions, they work because participants put real money on the line, which filters out noise and surfaces private knowledge. The result is a crowd-sourced probability estimate that consistently outperforms individual forecasters — as seen when Polymarket called the 2024 US presidential election hours ahead of major networks. They're not perfect (thin markets, correlated errors, and manipulation are real risks), but for calibrated, high-stakes forecasting, they're the best tool we have.