Prediction Markets Capture 27% of US Sports Betting During World Cup

Prediction markets accounted for roughly 27% of all legal U.S. sports-betting volume tied to the World Cup, according to data from H2 Gambling Capital cited by Bloomberg. That figure is up sharply from about 9% at the start of the year, underscoring how quickly platforms like Kalshi have carved out territory once dominated almost entirely by licensed sportsbooks.

The tournament, which ran from June 11 through July 19, gave prediction markets their biggest stage yet in the U.S. betting landscape. While traditional operators have not released their internal figures for the same period, the growth curve on the exchange side has been hard to miss, both in trading volume and in daily user counts.

Kalshi’s Rapid Rise

Kalshi has been the primary driver of that shift. The company posted an estimated $24.62 billion in total notional trading volume in June alone, a 70% jump from May, with sports contracts making up roughly 85% of that activity. World Cup-specific markets alone generated an estimated $17.81 billion on Kalshi over the course of the tournament. During the surge, Kalshi’s daily mobile app users reportedly surpassed both DraftKings and FanDuel, a notable milestone for a company that only recently pushed into sports-adjacent event contracts.

Separate analysis from Sportico, using notional volume data pulled from public Dune dashboards, found Kalshi holding around 83% of trading volume among CFTC-approved exchanges through the World Cup final — consistent with the 80%-plus share it has maintained for most of its two-year run. Polymarket’s regulated U.S. exchange came in second, rising to roughly 10% of that same pool.

Why the Comparison Is Murky — But the Trend Isn’t

Analysts caution that the 27% figure is an imprecise comparison, since prediction markets and traditional sportsbooks calculate trading activity differently, and licensed operators have not yet published their most recent internal numbers for the tournament window. Still, the broader direction is clear: platforms that operate as CFTC-regulated exchanges rather than state-licensed sportsbooks are pulling a growing share of sports-related wagering dollars, and doing so without the state-by-state licensing hurdles that traditional books must clear.

Newer entrants are adding to the pressure. Rothera, a joint venture between Robinhood and Susquehanna International Group that launched in June, processed an estimated $1.59 billion in its debut month and already accounts for roughly 7% of the U.S. prediction market. That kind of fast ramp suggests the space is far from settled, even with Kalshi’s commanding lead.

What It Means Going Forward

For an industry that has spent years fighting state-by-state battles over licensing, taxation, and market access, the rise of federally regulated prediction markets represents a structurally different kind of competitor. Bettors interested in tracking how this shift compares with standard sports betting can find more detail in Prediction Markets vs. Sports Betting, while newcomers curious about the mechanics behind these exchanges can start with the guide on how prediction markets work.

With major U.S. sports still ahead on the calendar and prediction markets now proven to scale during a global event like the World Cup, sportsbooks are likely to face continued pressure from exchanges that can list new contracts without waiting on state regulators. Whether that 27% figure holds, grows, or recedes once football, basketball, and baseball seasons ramp back up will be one of the more closely watched numbers in the industry over the next several months.