Prediction market platforms Kalshi and Polymarket posted a combined $50.6 billion in trading volume during July, an all-time high for the sector and a 7.8% jump from June's $47 billion.
Key Takeaways
- Kalshi led with $37.7 billion, while Polymarket revenue declined.
- World Cup markets drove July activity, but open interest fell sharply after the tournament ended.
Kalshi held onto its position as the largest of the two, pulling in $37.7 billion for the month, a 14% increase from June, according to data published by The Block.
The numbers told a different story for Polymarket's two platforms. The original offshore version of Polymarket saw its volume drop by 26% to $7.9 billion, while Polymarket US jumped by 54% to $5 billion. Combined, the two Polymarket platforms slipped from $14 billion in June to $12.9 billion in July.
Polymarket US removed its waitlist in May, opening the platform to any U.S. user and giving domestic traders a legal on-ramp they previously lacked. A Rutgers University statistician estimated earlier this year that U.S. users accounted for roughly 30% of activity on Polymarket's offshore platform over the 12 months ending April 30.
Much of July's surge traced back to the World Cup, which ran from June 11 through July 19. Kalshi's market on the Spain-Argentina final alone brought in close to $1.9 billion, while Polymarket's contract on the tournament winner attracted about $4 billion.
Since the July 19 final, interest in both Kalshi and Polymarket has significantly dropped. Open interest data from The Block shows that trading volume on Kalshi fell from its peak of $1.4 billion at the start of the month to roughly $788 million by the end. For Polymarket, combined wagering on both its platforms fell from around $550 million to $422 million.
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New York targets Kalshi with a $36-billion lawsuit
In more prediction market news, Kalshi has also suffered another setback in New York, as Attorney General Letitia James and Governor Kathy Hochul filed a suit against the platform, accusing it of operating unlicensed betting.
The filing seeks a court order barring Kalshi from offering those sports markets in New York without a gambling license, as well as financial penalties. New York is asking for at least $36 billion, a figure tied to the revenue Kalshi has generated from sports-related wagering. It also added a separate $100,000 penalty for each instance in which the company offered unlicensed sports betting in the state.
The case fits into a broader legal pattern shaping the prediction market industry, over whether the regulation of sports-event contracts should be in the hands of the state or the federal government. Because prediction markets are federally regulated, it means that they can offer contracts without holding gambling licenses.
New York's suit adds to a growing list of state actions challenging that federal framework, setting up a legal fight over whether sports-based prediction contracts should be treated as gambling subject to state law.
