The 2026 FIFA World Cup has been a massive catalyst for prediction market platforms, driving trading volumes to record highs in June. Companies like Kalshi and Polymarket reported multi-billion dollar surges, while newcomer Rothera quickly garnered significant volume. This surge tested the platforms’ capabilities under intense scrutiny from regulators and institutions, highlighting the growing importance of event contract exchanges in financial markets.
The 2026 FIFA World Cup, widely anticipated as the largest gambling event in history, has delivered on its promise, sending trading volumes on prediction market platforms soaring to record highs in June. This global soccer spectacle proved to be a significant catalyst for the burgeoning industry.
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Kalshi, a prominent prediction market platform, recorded an astonishing more than $31 billion in notional volume during the month of June. This represents a substantial 70% increase from May's total of $17.9 billion, according to user-collected data on Dune Analytics. Since the tournament's kickoff on June 11, Kalshi has consistently maintained daily volumes exceeding $1 billion.
Polymarket's international event contract exchange also celebrated a new monthly volume record, with notional trading surpassing $10.8 billion in June. This impressive surge successfully reversed a downward trend observed in April and May, when volumes had declined.
Furthermore, Polymarket's U.S. platform also saw robust activity, reaching over $3.5 billion in notional volume during June, a significant leap from its $1.77 billion total in May.
Team USA's Impact
As Team USA prepared to face Belgium in the round of 16 on Monday night, prediction markets buzzed with activity. Over $64 million on Kalshi and $122 million on Polymarket had been traded on the prospect of the U.S. winning the entire tournament, despite relatively low odds of 4.3% and 3% respectively on each platform.
The World Cup excitement also provided a crucial boost to Rothera, a new prediction market platform launched in June as a joint venture between Susquehanna International Group and Robinhood. Robinhood began routing specific World Cup contracts through its brokerage to Rothera, contributing to its rapid growth. In its inaugural month, Rothera generated $2 billion in notional trading volume, now accounting for 7% of the total U.S. prediction market volume, according to Bank of America.
Prediction market platforms universally capitalized on the World Cup's appeal to attract new users and boost engagement. Polymarket, for instance, launched a competition offering up to $2 million to participants who could craft a perfect World Cup knockout round bracket. Kalshi prominently advertised "Trade the World Cup" on its mobile platform's title in the Apple app store, highlighting the event as a key trading opportunity.
The elevated open interest—the total number of active, unsettled contracts—across these platforms further underscores the World Cup's impact. Kalshi's open interest now exceeds $1 billion, while Polymarket's stands just under $400 million, a consistently high level for its international platform in recent months.
While sports were the primary focus last month for event contract exchanges, their performance during this high-volume period offers crucial insights into how they might manage other contract topics in the future. Asaf Meir, CEO of Solidus Labs, a market integrity company partnered with Kalshi, emphasized the World Cup's significance. Meir noted that both regulators and institutions are closely monitoring the platforms' performance, asking if they are "safe enough? Is it mature enough? Does it have enough volume?" He concluded that the World Cup serves as a "huge pressure test to see whether indeed prediction markets are able to deliver their word on maintaining a level playing field for all investors for a long period of time in a sustained high-volume environment."
Disclosure: CNBC and Kalshi have a commercial relationship that includes customer acquisition and a minority investment.
