Americans secretly drove as much as $34 billion in offshore prediction market bets, new report claims

U.S. users are continuing to access prediction market platforms like Polymarket and Myriad Markets that are supposed to geo-fence the entire country, according to a new research report from Crane Zeng, a boutique consulting firm specializing in analytics, political strategy, and prediction markets.

On Thursday, the consultancy firm published a report claiming that some $11 billion to $34 billion of total offshore prediction market volume came from U.S. users. Polymarket, the second-largest prediction market following Kalshi, accounted for between $11 billion and $27 billion of that activity alone, the report said, calling that a "conservative" estimate.

"Based on current third-party estimates of industry growth, U.S.-based activity on offshore prediction markets could grow to an estimated $133 billion in annual volume by 2030, assuming constant relative market shares of regulated and offshore markets," an executive summary of the report said.

Prediction markets have exploded in popularity over the past two years, largely driven by market leaders Kalshi and Polymarket. These companies offer venues for users to place binary yes-or-no bets on the outcome of any event, from politics and economics to sports and entertainment. 

Bernstein, cited in the report, said in April that prediction market volume could grow to approximately $1 trillion by 2030, at an 80% compound annual growth rate.

For years, prediction markets typically operated as an academic concern, with the largest U.S.-based venue being the University of Iowa’s Iowa Electronic Markets platform, which operated with a no-action letter from and under strict oversight of the Commodity Futures Trading Commission. 

In theory, prediction markets offer an unbiased view of future outcomes, given that participants stake real money on their supposedly informed bets, rather than betting based on their desired outcome. 

Polymarket, which launched on the Polygon blockchain in 2020, was banned two years later from operating in the U.S. after serving American customers without the proper registration. At the time, in 2022, the agency treated event markets as highly-regulated swaps and kept a tight lid on the sector. 

The agency also attempted to block Kalshi from offering election-related markets in 2024. However, the startup sued its regulator and won on appeal, enabling it and other prediction market startups to expand in the U.S. Polymarket has since been granted CFTC approval to reenter the U.S. via a subsidiary after acquiring the regulated derivatives exchange QCEX.

While the CFTC now treats prediction markets with a lighter touch, as part of its support for innovative technology during the second Trump term, it still requires companies to register for and receive a Designated Contract Market (DCM) license. Unlicensed firms, including Polymarket’s global venue, are still banned from the U.S.

Behind the geofence

Crane Zeng notes that prediction markets have long been rumored to illegally serve U.S. users, who often access these platforms using VPNs.

"In 2024, offshore prediction markets accounted for 84.4% of the estimated $16.8 billion in combined annual volume across the platforms tracked here," the firm wrote. "In 2025, the offshore share fell to 60.9% of an annual total of $65.0 billion, with combined volumes nearly four times larger than in 2024."

According to the report, while there are non-blockchain-based venues that serve U.S. users without CFTC oversight, this activity is dominated by onchain protocols, including Polymarket, Opinion, Limitless, Overtime, Predict and other smaller exchanges. "Blockchain-based platforms are the most readily accessible, due to the lack of KYC and anonymity afforded by cryptocurrency wallets," the firm said. 

The report claims that 12.5% to 31.5% of U.S. prediction market volume occurs on offshore platforms, and that approximately 30% of Polymarket trading volume was attributable to U.S.-based users over the measured period. The report is based on trading volume provided by Dune Analytics.

The Block reached out to Polymarket for a comment on the report. 

Notably, U.S. venues have apparently "narrowed the gap with offshore" platforms, which previously dominated trading volume. CFTC-regulated firms Kalshi, Crypto.com, IBKR ForecastEx, Gemini) processed $74 billion in the measured 12 months, with Kalshi accounting for $70 billion of that, compared to $85 billion collectively from offshore platforms.

"Offshore platforms account for 54% of this total, down sharply from 84% in 2024," the report said.