Kalshi, Polymarket volumes rise 75% to $45B in June

Kalshi and Polymarket saw combined trading volume rise 75% month-over-month to $45 billion in June, driven by trading in World Cup-related contracts. The increase followed roughly $25.7 billion in combined volume in May.

Traders bought and sold contracts tied to match outcomes, tournament winners, goalscorers and other soccer propositions. High-profile matches and rounds with wide international interest concentrated liquidity and raised trade flows on both platforms.

Activity took place on online prediction-market platforms where contracts resolve to a fixed payout if a specified event occurs. Volume spikes tended to occur around key match windows when new information such as starting lineups, injuries or in-game developments affected prices.

Kalshi and Polymarket operate under different frameworks. Kalshi is a U.S.-based exchange regulated by the Commodity Futures Trading Commission and settles contracts in U.S. dollars. Polymarket has historically used cryptocurrency rails and decentralized finance infrastructure to handle settlements.

Both firms expanded their World Cup contract menus in June, offering short-term markets for individual matches alongside longer-term tournament propositions. The tournament schedule provided frequent settlement points and repeated trading events.

June’s volume growth showed higher average trade sizes and increased numbers of transactions on match days across both platforms.