Polymarket’s World Cup winner market has reached approximately $2 billion in trading volume ahead of the tournament’s June 11 kickoff, marking the first major sports event for prediction-market platforms since expanding beyond crypto and politics into mainstream betting.
Kalshi, the CFTC-regulated US prediction-market platform, has crossed $100 million in World Cup trading volume. The combined expansion reflects a dramatic acceleration: Kalshi and Polymarket processed less than $5 billion in monthly global trading volume in September 2025, but that figure rose to approximately $24 billion by April 2026.
On Polymarket, Spain and France are nearly tied at 16% implied probability each, followed by England at 11%, Portugal at 10%, and Argentina at 9%. Kalshi’s odds show a similar pattern: Spain at 16.5%, France at 16.2%, Portugal at 10.5%, England at 10.1%, and Argentina at 8.9%. The 48-team tournament spans 39 days and includes 104 matches.
The World Cup expansion highlights a regulatory fault line. The Commodity Futures Trading Commission asserts that sports prediction contracts fall within its jurisdiction as trading instruments. Several US states counter that such contracts constitute sports gambling and should be regulated under state frameworks. Polymarket’s main international exchange operates outside CFTC oversight and has barred US users, though the platform launched a separate US operation. Kalshi operates under CFTC regulation.
Alvin Kan, Chief Operating Officer of Bitget Wallet, framed the moment in broader terms: “The World Cup shows why this matters: billions of people are not only watching the same moments, but forming views, debating outcomes and acting on conviction in real time.”
Prediction-market contracts function as probability instruments. A contract trading at 40 cents implies a 40% probability of the outcome and pays $1 if that outcome occurs. Platforms maintain surveillance tools and market-integrity systems to detect suspicious activity, though neither Polymarket nor Kalshi has disclosed specific details of those systems or reported market manipulation during World Cup trading.
Critics characterize sports prediction markets as gambling products rebranded as trading. Supporters argue that federally regulated event contracts bring transparency and surveillance to informal betting markets that operate without oversight. The average monthly legal US sportsbook wagered $14 billion last year, providing context for the scale prediction markets are attempting to capture.
The regulatory debate centers on whether prediction contracts represent transparent price discovery or disguised gambling. Prediction markets can reflect momentum, public attention, fan loyalty, and uneven information access, creating potential for information asymmetries that traditional sports betting also contains. The World Cup will test whether regulators and platforms can establish durable frameworks for sports prediction markets in the US and internationally.
