What Is a Prediction Market? A Beginner's Guide
A prediction market is an exchange where contracts pay out based on real-world events — elections, sports, economic data, weather.
A prediction market is an exchange where the things being traded are not stocks or commodities but contracts that pay out based on the outcome of a future event. If you buy a contract for "Candidate X wins the 2028 election" at $0.40 and Candidate X wins, the contract pays $1.00. If they lose, it pays $0.00. The price of the contract — between $0 and $1 — can be read directly as the market's implied probability of the event.
This makes prediction markets unique. A poll asks a thousand people what they think; a prediction market asks anyone with money on the line what they're willing to bet. Because traders lose money for being wrong, prediction-market prices tend to incorporate information faster and more accurately than polls or pundit forecasts.
A short history
Informal prediction markets have existed for centuries — the Iowa Electronic Markets, run by the University of Iowa since 1988, is one of the oldest formal ones. After the rise of crypto, real-money prediction markets exploded in scale. Polymarket, launched in 2020, traded billions of dollars during the 2024 US presidential election. Kalshi, regulated by the CFTC, brought event contracts to the regulated US derivatives market in 2021.
Why they're often more accurate than polls
Markets aggregate information. Anyone who knows something — a tracking pollster, a campaign operative, a sports trainer — has an incentive to act on it. Their trades move the price. Decades of academic research (Wolfers and Zitzewitz, Hanson, Arrow et al.) have found that prediction markets generally outperform expert forecasts.
They aren't infallible. Markets can be thin, manipulated, or biased by retail enthusiasm. But over enough markets and enough time, they're a remarkably good probability machine.
Where to trade
Polymarket is the largest crypto-based prediction market — you deposit USDC and trade. Kalshi is the leading US-regulated platform, where you deposit USD via ACH. Manifold uses play-money. PredictIt is an academic political market.
Each has tradeoffs in liquidity, regulation, fees, and contract variety. Their status pages — like this one — let you check whether the platform is online before you try to trade.