Kalshi and Polymarket combined for a record $50.6 billion in trading volume in July, fueled largely by World Cup markets.
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 the way with $37.7 billion, up 14% from June
- Polymarket’s numbers were mixed: its offshore platform dropped 26% while Polymarket US jumped 54%
- World Cup markets drove much of the surge, and activity has cooled sharply since the tournament ended
What Happened
Kalshi held its position as the larger of the two platforms, pulling in $37.7 billion for the month according to data from The Block. Polymarket told a more mixed story. Its original offshore platform saw volume fall 26% to $7.9 billion, while Polymarket US, which removed its signup waitlist back in May and opened to any US user, jumped 54% to $5 billion. Combined, Polymarket’s two platforms slipped from $14 billion in June to $12.9 billion in July.
Much of July’s activity 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 drew roughly $4 billion.
That surge didn’t last. Since the World Cup final, trading has cooled noticeably on both platforms. Kalshi’s daily open interest fell from a peak of $1.4 billion early in the month to around $788 million by month’s end, while Polymarket’s combined open interest dropped from about $550 million to $422 million over the same stretch.
New York’s Lawsuit Against Kalshi
Kalshi is also facing a legal challenge in New York. State Attorney General Letitia James and Governor Kathy Hochul filed suit against the platform, alleging it has been operating unlicensed sports betting in the state. The filing seeks a court order barring Kalshi from offering sports-related markets in New York without a gambling license, along with financial penalties tied to the revenue it has generated there, plus an additional penalty for each instance of unlicensed activity.
The case is part of a broader legal fight over who gets to regulate prediction markets. Because these platforms operate under federal oversight, they’ve been able to offer sports-event contracts without state gambling licenses, and a growing number of states are now challenging that framework directly.