Major U.S. banks, represented by the Bank Policy Institute (BPI), are contemplating a lawsuit against the Office of the Comptroller of the Currency (OCC) to halt the issuance of trust charters to cryptocurrency companies. This potential legal action follows the OCC's conditional approval of trust bank charters for several crypto firms, including Circle and Ripple, in December 2025. The move has sparked concerns among traditional banks about regulatory arbitrage and unfair competition. The controversy centers on Interpretive Letter 1176, which redefined trust bank activities, easing charter access for crypto and fintech firms. Critics argue that the OCC bypassed formal rulemaking procedures, potentially violating the Administrative Procedure Act. The Conference of State Bank Supervisors and the Independent Community Bankers of America have also voiced opposition, fearing that these charters could undermine traditional banking standards. As the OCC prepares to implement rule amendments on April 1, the banking sector's response and potential litigation could mark a significant legal battle over the future of financial regulation in the U.S. The outcome will determine the extent to which crypto companies can integrate into the U.S. financial system under current regulatory frameworks.