JPMorgan Chase & Co., Bank of America Corp. and Citigroup Inc. said they’re halting purchases of Bitcoin and other cryptocurrencies on their credit cards. JPMorgan, enacting the ban Saturday, doesn’t want the credit risk associated with the transactions, company spokeswoman Mary Jane Rogers said.

Bank of America started declining credit card transactions with known crypto exchanges on Friday. The policy applies to all personal and business credit cards, according to a memo. It doesn’t affect debit cards, said company spokeswoman Betty Riess.

And late Friday, Citigroup said it too will halt purchases of cryptocurrencies on its credit cards. “We will continue to review our policy as this market evolves,” company spokeswoman Jennifer Bombardier said.