Woofun AI data shows that U.S. prediction market platform Kalshi recorded a June trading volume of approximately $9.4 billion, marking a 77% increase from May’s $5.3 billion and establishing a new all-time high.

Concurrently, Polymarket International’s volume grew from $3.5 billion to $4.3 billion during the same period.

The expansion of the 2026 World Cup to 48 teams significantly boosted single-match contract activity, with the Canada-Morocco Round of 16 match generating over $48 million on Kalshi and $26.8 million on Polymarket. Despite this liquidity surge, regulatory scrutiny has intensified. Multiple U.S. states argue for gambling regulation rather than CFTC oversight, while ESMA warned that certain event contracts may fall under existing binary options rules.