According to a study commissioned by the Coalition for Prediction Markets, Americans traded up to $34 billion on offshore prediction markets during the 12-month period ending in April 2026. The study, conducted by Rutgers professor Harry Crane, estimated that 12.5–31.5% of U.S. prediction market volume occurs on offshore platforms, with Polymarket alone accounting for $10.6–$26.7 billion of its $55.6 billion trailing 12-month trading volume from U.S. users.
Based on current industry growth projections, 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, the study said.