World Cup trading on prediction markets reaches $5.4 billion

World Cup wagering has sent prediction-market activity to record levels, with Kalshi and Polymarket reporting a combined $5.4 billion in trading tied to the tournament. The surge matters because it shows how event-contract platforms are becoming a larger part of sports betting, even as regulators debate how they should be treated.

Fortune reported that it reviewed data from leading prediction markets as of Thursday, less than two weeks into the tournament and with about a month of play still ahead. The activity spans platforms that let users trade contracts tied to sports results and other real-world outcomes.

Kalshi reported the largest total among the platforms cited by Fortune. The company said World Cup trading volume had reached $2.9 billion, including combination bets, and was still climbing.

That total has already passed some of Kalshi’s other high-profile sports markets, according to Fortune. The company recorded $2.51 billion in volume for March Madness and $685 million for this season’s Champions League.

Polymarket has also seen heavy World Cup betting. A person familiar with the company told Fortune that Polymarket’s World Cup wagers have produced $2.5 billion in cumulative trading volume since the market launched last July, making it one of the largest single markets in the platform’s history.

The same person said soccer-related trading on Polymarket’s global decentralized finance platform has topped $5 billion over that period. Fortune described Polymarket as a major competitor to Kalshi in prediction markets.

Robinhood gave Fortune a different measure of activity: contract volume. A spokesperson said Rothera, a CFTC-licensed exchange and clearinghouse run through Robinhood’s joint venture with Susquehanna International Group, has handled more than 500 million contracts since the start of the month, including 400 million since the World Cup opened on June 11.

The tournament has also shown the risks of betting on soccer outcomes, Fortune reported. Several early matches have produced unexpected results, including Spain’s 0-0 draw with Cabo Verde and Portugal’s draw with Congo.

Those results created large wins for some prediction-market traders. Fortune cited a Polymarket user named “BreakTheBank,” who wagered just under $300,000 that Portugal would not win against Congo and made nearly $1 million after the draw.

In another Polymarket trade cited by Fortune, a newly created wallet placed a $4 million bet that Spain would not beat Cabo Verde and ended with about $9 million. Fortune reported that the trade led to public questions over whether the wager reflected luck or access to information not available to the public.

The scale of those trades has added to scrutiny of prediction markets. Fortune reported that concerns about insider activity have grown as the platforms expand, while some countries have banned or blocked certain markets.

In the United States, Fortune reported, the growth of event contracts has fueled a dispute between federal regulators and state authorities. The central issue is whether these products should be treated more like financial contracts or like gambling that lacks state licensing.

This story draws on original reporting from Fortune.