Prediction Markets Smash Records as July Trading Hits $50.6B

Prediction markets reached a new milestone in July, with Kalshi, Polymarket, and Polymarket US collectively recording approximately $50.59 billion in monthly trading volume, reflecting growing interest in event-based markets as the FIFA World Cup captured global attention.

According to data from The Block, combined trading volume increased 7.8% from $46.95 billion in June, marking another month of strong growth for the sector.

Kalshi Maintains Market Leadership

Kalshi remained the largest prediction market platform during the month, posting approximately $37.7 billion in trading volume, a 14% increase compared with June.

Trading activity across Polymarket's platforms showed a mixed performance. The platform's international marketplace recorded $7.9 billion in monthly volume, representing a 26% decline, while Polymarket US saw trading surge 54% to approximately $5 billion.

Combined, the two Polymarket platforms generated around $12.9 billion in July, down from roughly $14 billion the previous month.

Polymarket US Expands Following Market Access

The sharp increase in activity on Polymarket US follows the platform's decision to remove its initial waitlist in May, allowing eligible U.S. users broader access after launching under the regulatory oversight of the Commodity Futures Trading Commission (CFTC).

The move provided American users with a regulated alternative for participating in prediction markets, replacing the need for some traders to rely on offshore platforms.

Earlier this year, Harry Crane, a statistician at Rutgers University, estimated that U.S. users accounted for roughly 30% of trading activity on Polymarket's international platform during the twelve months ending April 30, 2026.

World Cup Drives Trading Surge

Much of July's trading activity was fueled by the FIFA World Cup, which ran from June 11 to July 19.

Kalshi's market for the tournament final between Spain and Argentina generated approximately $1.9 billion in trading volume, while Polymarket's World Cup winner market attracted nearly $4 billion in wagers.

However, trading activity slowed after the tournament concluded.

Open interest across the three prediction market platforms declined from roughly $2 billion at the beginning of July to approximately $1.2 billion by the end of the month, indicating that many event-driven positions were closed following the championship.

Regulatory Challenges Persist

Despite record trading volumes, prediction markets continue to face legal and regulatory scrutiny in the United States, particularly regarding contracts tied to sporting events.

More than a dozen state regulators have accused Kalshi and Polymarket of offering unlicensed sports betting products and have taken steps to restrict event-based contracts within their jurisdictions.

Both companies, along with the CFTC, have challenged those actions, arguing that federally regulated prediction markets fall under federal jurisdiction rather than state gambling laws.

Growth Continues Amid Regulatory Uncertainty

July's record trading volumes underscore the growing adoption of prediction markets as they evolve from niche platforms into a broader financial product attracting both retail and institutional participants.

At the same time, the industry's long-term trajectory remains closely tied to regulatory developments.

Future court decisions and regulatory rulings defining the balance of authority between federal regulators and individual U.S. states could determine whether prediction markets continue expanding nationwide or face additional restrictions that limit their growth and product offerings.