New Study Estimates 30% of Polymarket’s Trading Volume Comes From Illegal U.S. User Activity

A new academic analysis finds that roughly 30% of total trading volume on prediction platform Polymarket originates from users based in the United States — a staggering figure, given that U.S. residents are barred from legally accessing the platform’s core crypto-powered offering.

The study, led by Rutgers University statistician Harry Crane, estimates that U.S. users funneled between $10.6 billion and $26.7 billion through Polymarket’s offshore platform over the 12-month study period, which ran from May 2025 to the end of April 2026. Crane tracked apparent U.S.-linked activity on offshore prediction marketplaces to map usage patterns, and found that many of Polymarket’s highest-volume markets center on U.S.-focused events, including national elections and domestic professional sports.

U.S. traders participate at disproportionately high rates in the platform’s sports trading vertical; the study calculates they account for roughly half of all activity in that category. “We’ve long known that some U.S. users access the platform, but we had no idea of the true scale — whether it was a handful of people or a meaningful share of total volume,” said Crane, who also serves on the CFTC’s Innovation Advisory Committee, a panel that guides federal regulators on technology’s impact on markets.

The industry lobbying group Coalition for Prediction Markets commissioned and funded the research, though Crane retained full independent editorial control over methods and findings. Major prediction market operators including Kalshi, Coinbase, and Crypto.com are members of the coalition; Polymarket is not.

One of the most popular prediction markets in the world, Polymarket lets users trade contracts tied to the outcome of future events ranging from NBA Finals championships to 5-minute bitcoin price fluctuations to military engagements in Iran. It has formed public partnerships with U.S.-based media outlets including Substack and Dow Jones, as well as major U.S. sports leagues such as Major League Baseball and the National Hockey League.

However, Polymarket’s original crypto-based primary platform has been banned for U.S. users since 2022, when federal regulators ruled it operated as an unregistered derivatives trading platform in violation of U.S. law. In December 2025, the company launched a separate, U.S.-licensed mobile prediction market branded as Polymarket US. Data from Pew Research shows Polymarket US recorded roughly $1.6 billion in trading volume in April 2026, compared to around $9 billion on the unregulated offshore platform — making the original offshore offering by far the larger of the two marketplaces.

To bypass U.S. geo-blocks, U.S. users are widely believed to mask their location to access the offshore site, most often using virtual private networks (VPNs) to hide their country of origin — a practice explicitly banned under Polymarket’s terms of service. This obfuscation has made it impossible to accurately measure U.S. activity on the platform until now, and Crane’s study marks the first major public effort to produce a formal estimate.

Lacking reliable tools to directly track the geographic origin of site traffic, Crane developed a methodology that leverages observed behavioral differences between U.S. and international traders. He analyzed factors including the time of day trades are executed and which markets users participate in (for example, U.S. traders are far more likely to trade on U.S. domestic sports than global users). The resulting estimate is not perfectly precise, but it provides the most comprehensive snapshot to date of hidden U.S. participation on the platform.

“It’s not a perfect measure, but it delivers a reasonable estimate of the share of volume coming from offshore trading by U.S. users,” said Charles Martineau, an associate professor of finance at University of Toronto Scarborough who has previously researched Polymarket trading behavior. “Using these kinds of indirect proxies is standard practice in finance research.”

Polymarket declined to comment on the study when reached. While the CFTC typically does not hold regulatory authority over offshore prediction markets, agency chairman Michael Selig told WIRED last month that he is willing to use extraterritorial jurisdiction to pursue bad actors on a case-by-case basis. It remains unclear whether the agency would pursue action against ordinary U.S. users who used VPNs to skirt the ban but did not engage in other illegal activity. The CFTC did not respond to requests for comment on the new study.

The issue of illegal U.S. trading on Polymarket gained high-profile attention in April, when the U.S. Department of Justice charged a U.S. special forces soldier with insider trading for allegedly using classified information about the planned capture of former Venezuelan president Nicolás Maduro to net roughly $400,000 in profits from Polymarket trades.

The study projects that U.S. activity on the offshore platform will continue to grow rapidly if Polymarket’s core crypto marketplace maintains its current market share, estimating that annual U.S. trading volume on the platform could hit $133 billion by 2030.