Prediction Markets Shatter Records With $12.2 Billion in Weekly Volume and $1.48 Billion in Open Interest as World Cup Betting Surges

The prediction market industry is experiencing a moment it may look back on as its real inflection point. The week ending June 15 produced simultaneous all-time highs in virtually every key metric the sector tracks — weekly trading volume, open interest, daily fees, and active user counts — with data published by a16z crypto confirming the sector has undergone a roughly sixfold expansion in open interest over the past 12 months alone.

Total notional volume across prediction markets hit $12.2 billion during the week, with sports-related contracts accounting for $5.8 billion — nearly half the entire total. The 2026 FIFA World Cup, currently underway across the United States, Canada, and Mexico, has emerged as the single largest catalyst, drawing in a wave of new users who are placing bets on group stage results, individual match outcomes, and tournament advancement markets through platforms like Kalshi and Polymarket.

The Numbers Behind the Milestone

Open interest climbed to a record $1.48 billion as of the week ending June 15, according to data aggregated from Dune Analytics. That figure measures the total value of contracts that remain active and unresolved — a measure of how much capital is currently committed and at risk across the sector, not just how much has traded hands. The sixfold increase over the prior year suggests users are holding longer-duration positions rather than simply turning over short-term trades.

Weekly fees hit $76.8 million, also a record. Active users reached 426,975 for the week — another all-time high. Kalshi and Polymarket accounted for the majority of total activity, with smaller platforms including Opinion, Limitless, and Myriad trailing significantly. The concentration of volume on the two leading platforms reflects a market that is still consolidating even as it expands rapidly. Kalshi’s promo code and Polymarket’s promotions have attracted significant new signups as the World Cup has drawn in casual sports bettors who may not have otherwise engaged with the prediction market format.

What the World Cup Is Doing to Prediction Markets

The World Cup is providing prediction markets with the kind of sustained, high-interest event that turns casual users into habitual traders. Unlike a single NFL game or an individual playoff series, the tournament runs continuously for weeks, creating a constant stream of new markets to trade and a consistent reason for users to return to the platform. Sports contracts now represent the industry’s largest category by volume, surpassing political and economic event contracts that historically dominated the space.

For the industry’s regulatory critics, that shift is precisely the problem. More than 41 state attorneys general have filed comments with the Commodity Futures Trading Commission arguing that sports-related prediction markets are functionally indistinguishable from traditional sports betting and should be regulated under state gambling law rather than federal derivatives law. The CFTC has countered that it holds exclusive jurisdiction over CFTC-designated contract markets. That legal battle is playing out across courts in multiple states simultaneously.

Implications for the Sports Betting Industry

Traditional sportsbook operators are watching the sector’s growth with a mix of competitive concern and strategic interest. DraftKings and FanDuel both launched prediction market products of their own following Kalshi’s success, though each has subsequently navigated regulatory challenges in states that classify their prediction market offerings as unauthorized gambling. The distinction between a prediction market and a sportsbook has become one of the defining legal questions of the current sports betting era.

For bettors looking to participate in the space, prediction market platforms offer a different format than traditional sportsbooks — binary contract structures, often lower fees, and access to markets that go well beyond standard betting lines. As the World Cup continues and volume stays elevated, the sector is likely to set additional records before the tournament concludes. The differences between prediction markets and sports betting continue to be debated in courtrooms, regulatory agencies, and newsrooms across the country.