Crypto firms have been left scrambling to find banking partners after the collapse of three crypto-friendly lenders in the U.S. last month, creating a risk their business will become concentrated in smaller financial institutions. It is a scenario that concerns U.S. regulators, who have expressed doubt about the safety and soundness of bank business models that are highly focused on crypto clients after Silvergate Capital Corp, Signature Bank and Silicon Valley Bank imploded. U.S. regulators have also told banks to be alert for liquidity risks coming from crypto-related deposits, which could be subject to rapid outflows if customers try to redeem their crypto assets for real money.