World Cup Frenzy Propels Prediction Market Volumes to Staggering New Heights

The 2026 FIFA World Cup, widely anticipated to be the most significant gambling event in history, has indeed triggered an extraordinary boom in trading volumes across various prediction market platforms throughout June.

Leading this monumental surge, Kalshi reported a staggering $31 billion in notional volume during the month, marking a formidable 70% increase from its May total of $17.9 billion. Since the start of the soccer tournament on June 11, Kalshi has consistently recorded daily volumes exceeding $1 billion, according to user-collected data on Dune Analytics.

Similarly, Polymarket's international event contract exchange established a new record high in monthly volume, with notional trading surpassing $10.8 billion in June. This robust performance effectively reverses a prior downturn experienced in April and May.

Concurrently, Polymarket's U.S. platform also saw substantial growth, registering north of $3.5 billion in notional volume for the month, a considerable leap from $1.77 billion in May.

A datawrapper chart titled "Notional volume jumped for all platforms after the World Cup started" would be placed here, illustrating the dramatic increase across platforms following the tournament's commencement.

Team USA's Tournament Quest Fuels Trading

As Team USA prepared for its round of 16 match against Belgium, significant trading activity revolved around its tournament prospects. Over $64 million on Kalshi and $122 million on Polymarket was traded on the U.S. winning the World Cup, despite the odds of such an outcome being relatively low at 4.3% and 3% on each platform, respectively.

The global football fever also provided a crucial launchpad for Rothera, a new prediction market platform. A joint venture between Susquehanna International Group and Robinhood, Rothera debuted in June, with Robinhood routing certain World Cup contracts to the platform. Rothera quickly amassed $2 billion in notional trading volume within its inaugural month and now accounts for 7% of the total U.S. prediction market volume, according to Bank of America.

A datawrapper chart titled "Rothera sees higher volume second week of June" would be placed here, detailing Rothera's rapid volume growth after its launch.

All major platforms actively capitalized on the World Cup's appeal to boost user engagement. Polymarket launched a competition offering up to $2 million for participants who could perfectly predict the World Cup knockout round bracket. Kalshi prominently featured "Trade the World Cup" in the title of its mobile application on the Apple App Store, drawing users in.

The heightened level of open interest—representing the total number of active, unsettled contracts on these platforms—further reflects the immense excitement generated by the World Cup. Kalshi's open interest now stands above $1 billion, while Polymarket's open interest remains elevated at just under $400 million.

While sports dominated event contract exchanges last month, the platforms' seamless handling of this unprecedented volume surge serves as a crucial test case for how they might manage other contract topics in the future.

Asaf Meir, CEO of Solidus Labs—a market integrity company that has partnered with Kalshi—highlighted the World Cup as a pivotal moment for these platforms. He noted that both regulators and financial institutions are closely observing their performance, questioning, "Is it safe enough? Is it mature enough? Does it have enough volume?" Meir stressed that the World Cup presents a significant "pressure test" to demonstrate prediction markets' capability to maintain a level playing field for all investors within a sustained high-volume environment.

Disclosure: CNBC and Kalshi have a commercial relationship that includes customer acquisition and a minority investment.