The two largest U.S. banks, JPMorgan Chase and Bank of America, have announced that they will no longer allow cryptocurrency purchases on credit cards they have issued.

The ban went into effect on Saturday and includes personal and business credit cards, according to multiple media reports. Debit cards are not affected.

According to the reports, the banks are concerned chiefly about the volatility of cryptocurrencies. They worry that customers will be unable pay for purchases made on credit if the currency or token drops in value, leaving the bank holding the bag.

Financial institutions are also wary of the potential that customers could be buying cryptocurrency for money-laundering purposes.

Citigroup currently is considering its policy regarding cryptocurrency purchases using credit cards. Capital One and Discover Financial Services have already banned the practice.