Senator Elizabeth Warren, Ranking Member of the U.S. Senate Committee on Banking, Housing and Urban Affairs, sent letters to 15 major credit card issuers requesting information on fees charged when consumers use credit cards on sports-betting and prediction market platforms. The inquiry focuses on undisclosed or poorly disclosed charges, particularly where transactions are treated as cash advances, which can trigger higher fees and immediate interest accrual, and asks whether issuers restrict these uses or why they continue to allow them. The letters argue that these practices can leave consumers with expensive, compounding debt, including cases where a USD 20 account funding transaction can generate a USD 10 fee. The probe follows an earlier Warren investigation that, according to the release, led around 80 percent of the sports gambling market to stop accepting credit card transactions. Responses are requested by May 15, 2026.