The 2026 FIFA World Cup served as a catalyst that propelled prediction markets to a fundamentally new level. By my estimates, the combined trading volume on leading platforms — Kalshi and Polymarket — exceeded $50 billion in June, setting an absolute record for this segment. These are not just numbers, but a clear signal of a paradigm shift in the sports betting industry.
Kalshi and Polymarket: Dominance That Cannot Be Ignored
Kalshi, a platform focused on the regulated U.S. market, showed staggering momentum. In June, its trading volume surpassed $31 billion, a 70% increase from May. Notably, 85% of this turnover came from sports contracts. This indicates that users perceive Kalshi not as an abstract forecasting tool, but as a direct alternative to traditional bookmakers.
Polymarket, an international decentralized platform, also broke its monthly record, reaching $10.8 billion. Its regulated U.S. version added another $3.5 billion to that. Combined with the Rothera project (a joint venture between Robinhood and Susquehanna), which processed $2 billion, we see the consolidated power of this new financial instrument.
Traditional Bookmakers Are Losing the Battle for Audience
The contrast with classic betting operators is stark. Researchers from Eilers & Krejcik predicted that legal U.S. sportsbooks (DraftKings, FanDuel, BetMGM, Caesars) would accept bets totaling $2.8-4.3 billion for the entire tournament. For comparison, Kalshi alone collected $7.4 billion before the group stage even ended. User activity on traditional platforms dropped by 32-41% after the initial surge.
Meanwhile, Kalshi and Polymarket accounted for 78.5% of all installations among the six largest betting and prediction apps. A year ago, their combined share was a mere 6%. Kalshi's audience grew by 36% in just two weeks at the end of June — largely due to its partnership with FIFA and integration with Fox Sports.
In my view, we are witnessing not just a temporary spike, but a structural shift. Prediction markets offer users transparency, liquidity, and the absence of betting limits, making them far more attractive to large players than traditional bookmakers. The pressure from U.S. gambling associations demanding a ban on such platforms only confirms their growing threat to the established industry. The 2026 World Cup was just the first act of this transformation.