Kalshi's June trading volume reached a record nearly $9.4 billion, with the World Cup being the biggest driving force

According to DefiLlama data, Kalshi's trading volume in June reached nearly $9.4 billion, setting a new historical high, a significant increase from about $5.3 billion in May. Polymarket International's trading volume during the same period also rose from about $3.5 billion to approximately $4.3 billion. The 2026 FIFA World Cup will kick off on June 11, expanding to 48 teams for the first time, and according to CNBC, it has become the biggest driving force behind June's prediction market trading. Trading activity during the knockout stage is particularly active; as of the time of writing, the Round of 16 match between Canada and Morocco generated over $48 million in trading volume on Kalshi, and over $26.8 million on Polymarket.

Meanwhile, prediction markets in the United States face ongoing legal and regulatory disputes, with nearly a dozen states taking action against Kalshi and Polymarket. CFTC Chairman Selig has accused the states of illegal enforcement actions against federally regulated exchanges. In Europe, ESMA reminded companies last Friday that many event contracts may be subject to existing binary options restrictions.