Kalshi’s trading volume reached nearly $9.4 billion in June, a record high and up from about $5.3 billion in May, according to DefiLlama data. According to ChainCatcher, Polymarket International’s trading volume also rose over the same period, increasing from about $3.5 billion to about $4.3 billion.
CNBC reported that the 2026 FIFA World Cup, which began on June 11 and expanded to 48 teams for the first time, became the biggest driver of prediction-market trading in June. Trading was particularly active during the knockout stage; as of publication, a Canada vs. Morocco round-of-16 match generated more than $48 million in volume on Kalshi and more than $26.8 million on Polymarket.
The growth comes as prediction markets face ongoing legal and regulatory disputes in the United States. More than a dozen states have taken actions against Kalshi and Polymarket, while CFTC Chair Selig accused states of illegally enforcing actions against federally regulated exchanges.
In Europe, the European Securities and Markets Authority said last Friday that many event contracts may already be restricted under existing binary options limits.