Kalshi and Polymarket recorded combined trading volume of $53 billion in July ahead of the U.S. midterm elections in November. According to Odaily, the total more than doubled from $26 billion in May, with most trading concentrated in sports markets.

Political trading accounted for a smaller share of activity. Polymarket averaged about $2 billion in monthly political trading this year, while Kalshi averaged less than $300 million. By July, trading on which party would control the House and Senate had exceeded $30 million.

The U.S. Commodity Futures Trading Commission had previously barred Kalshi from listing contracts on congressional control and proposed classifying election contracts as gambling. The agency withdrew that proposal in February and issued a proposed framework for structured event contracts on June 10 that would not classify election contracts as gambling. That month, Kalshi launched its Midterms Hub, displaying individual congressional-district market probabilities alongside polling averages.

Chuck Todd, a former NBC News political director and former host of Meet the Press, is scheduled to host the NEXTPredict summit in New York on October 22 and 23. He said he wanted to explore how polling firms and prediction markets affect one another and whether trades are used for hedging or entertainment. The Anti-Corruption Data Collective said a $3,500 bet could move prices by at least five cents in 97% of midterm-related markets. Morgan Stanley’s analysis of more than 72 million Kalshi trades found that prices were close to outcomes.