Traders have poured more than $2 billion into World Cup winner markets on Kalshi and Polymarket. Here is how prediction markets work, how they differ from a sportsbook, and where they are legal.
While the regulated sportsbooks take the headlines, a parallel market has exploded around the 2026 World Cup: prediction markets. Traders have moved more than $2 billion through Kalshi and Polymarket on the tournament-winner market alone. If you have searched "Kalshi" or "Polymarket" this month, here is how they actually work, how they compare to a traditional sportsbook, and the legal picture in the US.
Prices, volumes and legal status below reflect mid-June 2026 and change quickly - confirm the current position before trading.
What a Prediction Market Is
Instead of betting against a bookmaker, you trade contracts against other people. Each contract on an outcome ("France to win the World Cup") trades between $0.01 and $0.99, and the price is the market's implied probability. France trading at $0.18 means the market prices them at roughly an 18% chance. If they win, each contract settles at $1; if they do not, it settles at $0.
The key difference from a sportsbook: there is no fixed bookmaker margin baked into a price you must accept. You buy and sell against other traders, and you can sell your position before the event settles to lock in profit or cut a loss - something a fixed sportsbook bet does not let you do.
Polymarket vs Kalshi
Kalshi is a CFTC-regulated US exchange. You fund your account with a debit card or ACH bank transfer in dollars - no crypto required - which makes it the more accessible option for most US users. As of mid-June 2026 it is available in 40+ states and carries the majority of US prediction-market volume on the World Cup.
Polymarket is the larger market globally and runs on crypto: you deposit USDC stablecoin over the Polygon blockchain. Its US exchange became CFTC-approved in late 2025, but its state-level picture is messier (more below). Polymarket's World Cup winner market alone has traded billions in lifetime volume with hundreds of millions in liquidity.
On the numbers the two broadly agree: in mid-June both had France around 18-19% to win, Spain around 13% and Argentina or Portugal around 11%. That is close to, but not identical to, the sportsbook odds - and the differences are where cross-market bettors look for an edge.
Prediction Markets vs Sportsbooks
- Pricing. Sportsbooks set a line with margin built in; prediction-market prices are set by supply and demand and tend to carry lower effective margin on big, liquid markets.
- Cash-out flexibility. You can trade out of a prediction-market position any time before settlement. A sportsbook only offers cash-out when and at the price it chooses.
- Market depth. Sportsbooks offer far more bet types - correct score, props, same-game parlays. Prediction markets concentrate on cleaner yes/no questions (winner, to reach the final, to win the group).
- Bonuses. Sportsbooks hand out welcome offers and boosts; prediction markets generally do not, though they sometimes run fee promotions.
- Liquidity risk. On a thin market your trade can move the price against you; on a multi-hundred-million-dollar World Cup winner pool, that is rarely an issue.
Are Prediction Markets Legal in the US?
This is the crucial part, and it is moving fast:
- Kalshi operates under federal CFTC regulation and is live in more than 40 states - including several that do not have legal sportsbooks, which is a big part of its appeal in states like California and Texas. As of mid-2026, Minnesota is the notable state moving to ban it, with a prohibition set to take effect later in the year.
- Polymarket is CFTC-approved at the federal level but faces a patchwork of state challenges - cease-and-desist orders and litigation in multiple states. As of mid-June 2026 it was unavailable in several, including Arizona, Illinois, Massachusetts, Maryland, Michigan, Montana, New Jersey, Nevada and Ohio.
Because the situation is being actively litigated, where each platform operates can change month to month. Always check the current status for your state before depositing.
Should You Use One?
Prediction markets suit you if you want lower effective margins, the ability to trade out of a position, and clean winner or qualifier markets - or if you live in a state without legal sportsbooks. Stick with a traditional sportsbook if you want prop depth, same-game parlays, live in-play betting and welcome bonuses. Plenty of bettors use both: prediction markets for the outright, a sportsbook for everything else.
For the sportsbook side, see our best World Cup betting sites and apps and our guide to the odds. New to the markets themselves? Our guide to betting a single match walks through the basics.
Bet Responsibly
Trading contracts is still gambling - being able to sell out early does not change that you can lose. Set a budget, do not chase, and use the responsible-play tools each platform provides. See our notes on setting deposit limits. For adults 21 and over. If gambling stops being fun, call 1-800-GAMBLER.