An event contract pays out depending on whether a specific event happens: "Will the Fed cut rates in June?", "Will Team A win the final?". It's the building block of every prediction market.

What is an event contract?

YES and NO

Most event contracts are binary:

  • YES pays $1 if the event happens;
  • NO pays $1 if it doesn't;
  • the other side gets $0.

The price as a probability

The price in cents reads as a probability: YES at 35¢ ≈ a 35% chance.

Regulation in the US

In the US, event contracts listed on a designated contract market are regulated by the CFTC under the Commodity Exchange Act, which the agency explains on cftc.gov. That's how Kalshi and Polymarket US operate, with each contract type certified with the regulator (example filing).

Some states argue that sports event contracts are really sports bets, and the question is being fought in court; in Nevada a judge barred Polymarket's sports, election and entertainment contracts on May 29, 2026 — see Polymarket legal states.

Example

An event contract asks: "Will monthly CPI inflation be above 0.3%?" YES trades at 45¢. You buy 100 for $45. The statistics agency reports 0.4%: you receive $100. If it had reported 0.3% or less, you'd receive nothing.

Next step

In the United States, the regulated route is the Polymarket US app. Read our guides on signing up and depositing to get started, start small and only use money you can afford to lose.