TERM
Prediction market
An exchange where an event outcome trades as a contract priced from $0 to $1, and the price comes from traders' deals, not a bookmaker's analyst.
A contract price of $0.45 is equivalent to odds of 2.22. Polymarket runs on USDC and is open globally; Kalshi is regulated in the US. An exchange earns from fees, doesn't limit players and is constrained only by order book depth: the volume of contracts at the price you need.
An exchange price reacts to the match more slowly than a bookmaker's, so surebets involving it live longer: a median of 4.1 seconds versus 2.1, according to Dozor data for September 6, 2026. More on the page about surebets with Polymarket and Kalshi.