Prediction Markets Hit Record $4.1 Billion in Daily Trading, Sports Lead the Way

Prediction markets have hit an all-time high in trading volume, with sports events driving a significant portion of the activity. In October, the industry saw an average daily trading volume of $4.13 billion, a 55% increase from the previous month. Sports event contracts accounted for $3 billion in daily volume, making up 78% of all trading. Non-sports trading also saw a significant increase, climbing 55% to an average daily volume of $843 million. The election cycle was a major factor in this surge, with Kalshi seeing about $2.6 billion in midterm trading volume overall on election night.

Open interest, the total value of active, unsettled contracts traders are currently holding, reached $3.27 billion in October, up 45% from September and a record high. Individual operators also saw substantial growth. Polymarket's average daily volume rose 50% from the previous month to $655 million, a staggering 395% increase from the same month in 2025. Other platforms registered $309 million of combined average daily volume, a 56% monthly increase from September. These other platforms hold about 7% market share. Sports continue to be the main driver in prediction market growth, with open interest on sports contracts climbing 83% in October.

Despite the growth, prediction markets face regulatory challenges. New York Attorney General Letitia James (D) alleges Kalshi’s “combo” products actually function as parlay wagers, accusing the company of secretly taking sides on contracts. Kalshi and other prediction markets have consistently maintained that their offerings are different from traditional sports betting and are regulated solely at the federal level by the Commodity Futures Trading Commission. With differing opinions from appeals courts concerning prediction markets, New Jersey has asked the Supreme Court to review the issue.