Clear answers about prediction markets
Each guide answers one question: a short answer first, then the detail, with a worked example using real numbers. Guides show when they were last reviewed.
Basics
- How to Read Prediction Market Odds: Price, Spread and Fees
A prediction market price is an implied probability: a YES contract at 62¢ pays $1 if the event happens, so the market prices it at about 62%. Buyers pay the ask, sellers get the bid, and taker fees raise the break-even. On Kalshi, a 62¢ taker buy needs a 63.65% win rate to break even.
Legal
- Are Prediction Markets Legal in the US? (November 2026)
As of November 10, 2026, prediction markets are legal under federal law when run as CFTC-regulated exchanges, such as Kalshi and Polymarket US. States argue sports contracts are gambling. Courts have blocked contracts in Michigan, Nevada and Washington, federal appeals courts are split, and three petitions await the Supreme Court.
Data and tools
- How accurate are prediction markets?
Our calibration study of resolved Polymarket markets, one day and one week before close.
- Break-even calculator
The win rate a contract needs after Kalshi or Polymarket fees.