Prediction Markets Reach $68 Billion in Monthly Volume as Sportsbook Shares Decline

Trading activity on sports prediction markets nearly doubled during the month football returned, with combined notional volume reaching approximately $68 billion, according to data from Aldrin Research. The surge came as shares of the two largest U.S. sportsbook operators fell to multi-year lows.

Sports Contracts Drive Market Growth

The $68 billion figure includes trading in sports contracts and combination contracts across the exchanges tracked by Aldrin Research. Notional volume represents the total value of contracts traded and does not equal revenue or profit generated by the platforms.

The increase highlights the growing competition between prediction markets and traditional online sportsbooks. Prediction markets allow participants to trade contracts tied to the outcome of future events, while sports betting platforms typically accept wagers against bookmaker-set odds.

Kalshi Maintains Market Lead

Kalshi remains the largest platform in the segment, although competing exchanges recorded faster growth during the period. The expansion coincided with the return of football, one of the most heavily followed sports in the U.S., which helped increase interest in event-based trading.

Sportsbook Stocks Under Pressure

The rise in prediction-market activity occurred as shares of the two biggest U.S. sportsbook operators declined to multi-year lows. The contrasting performance has intensified debate over whether prediction markets could capture a greater share of consumer activity currently directed toward conventional sports wagering platforms.

Market performance is likely to depend on regulatory treatment, contract availability, liquidity and the ability of platforms to attract and retain users as the sports calendar progresses.