Bailey said he was concerned some U.S. stablecoins could not be readily turned into ​dollars without ​going through a ⁠crypto exchange, potentially limiting their convertibility in a crisis.But if stablecoins became widely used for cross-border payments, then during a crisis hard-to-convert ​U.S. stablecoins could flow to jurisdictions such as Britain which intend to have robust obligations for convertibility, he said.