Kalshi Posts Record June Volume As World Cup Drives Prediction Market Boom

Prediction market platform Kalshi recorded its highest-ever monthly trading volume in June, with the expanded FIFA World Cup serving as the primary catalyst behind the surge.

World Cup Fuels Record Numbers

Data from DefiLlama shows Kalshi processed nearly $9.4 billion in trading volume during June, up from about $5.3 billion in May. Polymarket International also grew, reaching roughly $4.3 billion from $3.5 billion the previous month. The tournament, which began June 11, is the first World Cup to feature 48 teams rather than the traditional 32, and has become the single biggest driver of prediction market activity so far this year.

Knockout Matches Draw Heavy Betting

Individual matches are generating substantial trading volume. Canada’s Round of 16 matchup against Morocco had produced more than $48 million in volume on Kalshi and over $26.8 million on Polymarket at the time of reporting. A market tracking the United States’ Round of 16 outcome had drawn more than $2.1 million on Kalshi and around $1.6 million on Polymarket.

Legal Fight Over Regulation Continues

The volume surge comes as prediction markets face mounting regulatory pressure in the US. Close to a dozen states have taken action against companies including Kalshi and Polymarket, with some seeking to shut the markets down and others aiming to apply gambling laws and state tax rules. Federal regulators have pushed back firmly, with CFTC Chair Michael Selig accusing states of pursuing illegal enforcement actions and asserting that Congress gave the agency exclusive authority over commodity derivatives markets, including prediction contracts.

Industry Pressure And European Scrutiny

In June, casino operators, tribal groups and labor organizations asked Congress to exclude sports-event contracts from CFTC oversight through an amendment to the CLARITY Act, arguing they should fall under state gambling regulation instead. Separately, European regulators at ESMA said this week that many event contracts may already fall under existing restrictions on binary options, regardless of how they are labeled.