Kalshi, Polymarket and Robinhood's new Rothera venue combined for more than $50 billion in trading volume in June, dwarfing the handle traditional US sportsbooks are projected to take across the entire World Cup. The tournament has become the clearest evidence yet that event contracts are competing with regulated betting, not sitting beside it.
Kalshi, Polymarket and Robinhood's new Rothera venue combined for more than $50 billion in trading volume in June, dwarfing the handle traditional US sportsbooks are projected to take across the entire World Cup. The tournament has become the clearest evidence yet that event contracts are competing with regulated betting, not sitting beside it.
The 2026 World Cup has produced a breakout month for prediction markets, with Kalshi, Polymarket and the newly launched Rothera together trading more than $50 billion in June, according to figures compiled by CoinDesk and PYMNTS. Set against what regulated sportsbooks expect to take from the same tournament, that number is the clearest sign yet that event contracts have moved from the margins of American sports betting to its centre.
Kalshi led the field. The exchange recorded around $31 billion in total notional volume in June, an increase of more than 70% on May, with sports contracts accounting for roughly 85% of the total. Polymarket, which operates a large international business alongside a US platform, set a monthly record of $10.8 billion in international volume. Its US arm logged $3.5 billion, close to double its May figure.
Rothera, the newest entrant, a joint venture between Robinhood and Susquehanna that launched in June, processed around $2 billion in its debut month, enough to capture roughly 7% of US prediction-market share, according to Bank of America.
Against those numbers, the regulated sports-betting industry's own World Cup looks modest. US legal sportsbooks are projected to handle between $2.8 billion and $4.3 billion across the tournament's 104 matches, roughly one-tenth of the volume flowing through prediction markets over the same period, a gap of an order of magnitude.
The incumbents are not struggling. Christian Cipollini of BetMGM called the tournament strong for the sportsbook: "This World Cup has been record-type handle stuff for us this whole time."
There is also a demographic story inside the data. According to analytics firm Apptopia, Kalshi's female user base grew 106% during the tournament, outpacing 54% growth among male users, and lifting women to 33.3% of the platform's users by late June. That compares with a female share of around 22% to 23% at DraftKings and FanDuel.
The established betting operators are not watching from the sidelines. DraftKings launched its own event-contract exchange, DKeX, built on the Railbird platform, in June, having already moved to ban US credit-card deposits ahead of its prediction-market entry. FanDuel operates a product called FanDuel Predicts in partnership with the derivatives marketplace CME Group. Both moves acknowledge that the exchange model, regulated federally by the Commodity Futures Trading Commission (CFTC) rather than state by state, carries structural advantages the sportsbooks want access to. Overseeing that federal question is the CFTC itself, whose chair, Michael Selig, is developing a framework for event contracts that will shape how squarely the exchanges can compete with the state-licensed sportsbooks.
The 10-to-1 Volume Gap Is a Regulatory Arbitrage, Not a Fair Fight
The roughly 10-to-1 volume gap on the same event is not simply a story of a better product; it reflects two different regulatory regimes competing for the same customer. Sportsbooks operate under state licences, state taxes and state-by-state responsible-gambling rules; the exchanges operate under the CFTC's federal commodities framework, which was not designed with sports betting in mind. Until that asymmetry is resolved, every dollar that moves from a sportsbook to an exchange is partly a move from a more heavily regulated venue to a less heavily regulated one. If the rules will not be levelled down to the sportsbooks, they intend to climb up to them, which is why DraftKings and FanDuel have launched exchanges of their own.
Notional Volume Is Not Revenue, and the Comparison Flatters the Exchanges
The $50 billion figure deserves scrutiny before it becomes received wisdom. Kalshi's $31 billion is total notional volume, the face value of contracts traded, not the margin the platform keeps, and an exchange that matches buyers and sellers monetises a thin fee on turnover rather than the hold a sportsbook books on losing bets. The comparison matters, because volume is where liquidity and network effects come from, and liquidity is the moat in an exchange business. But anyone reading the 10-to-1 volume gap as a 10-to-1 revenue gap is misreading it. The exchanges have won attention and turnover; whether they convert that into durable profit is a separate question.
The Female-User Surge Is the Most Strategically Important Number
The shift in Kalshi's user base may matter more for the long term than the headline volumes. Women growing to a third of the platform, against roughly a fifth at the incumbents, points to the exchanges reaching demographics that traditional betting has spent years and vast marketing budgets failing to convert. If that pattern holds beyond the novelty of a World Cup, it changes the competitive map, because it suggests the exchange format itself, framed as trading rather than betting, appeals to customers the sportsbook brand does not. The caveat is that a single tournament is a weak basis for a trend, and retention after the final whistle is unproven. But of all the numbers from June, this is the one the incumbents should study hardest.
Federal Clarity Will Decide Whether This Is a Structural Shift or a Spike
Everything about June's numbers is provisional until the regulatory question is settled. The framework Selig is developing will determine whether the exchanges keep their current latitude or are pulled toward the same integrity, taxation and responsible-gambling obligations that bind the sportsbooks. The direction of travel elsewhere is not toward leniency: Italy has just ordered its internet providers to block Polymarket and hundreds of other domains. Sporting integrity will feature heavily, because a market where sports contracts already make up around 85% of Kalshi's volume is, functionally, a sports-betting market, and the safeguards built for regulated books do not stop mattering because the venue is a federal exchange. The state-licensed operators have spent a decade building compliance infrastructure; the exchanges have built liquidity first. June showed which of those wins attention. Whether it wins the market will be decided in Washington, not on the pitch.
