Moody’s has lowered the credit ratings of 15 major banks.

The downgrades announced on Thursday included Bank of America, JPMorgan Chase and Goldman Sachs in the US and Barclays, Deutsche Bank and HSBC in the European Union.

Moody’s said the banks’ long-term prospects for profitability and growth were shrinking.

The ratings agency said it was especially concerned about banks with significant financial markets businesses.

These banks were vulnerable to “outsized losses,” Moody’s global banking managing director Greg Bauer said in a statement.

The banks are all major players in the global stock and bond markets, which have become extremely volatile.

Bauer pointed out, however, that some of the banks, like JPMorgan Chase and HSBC, have reliable buffers in more stable businesses which could act as “shock absorbers” during a crisis.

The downgrades reflect Moody’s concern over the ability of the banks to repay their debts during times of crisis. Moody’s had said in February it was considering downgrading the credit ratings of major banks in the US and in Europe.

A downgrade usually means banks will have to pay more for debt. Investors demand higher interest for riskier debt, which is what the downgrades represent. However, with interest rates already at rock-bottom levels, the downgrades may not affect the cost of funding for the banks that much.

In a sign that investors were taking the news in stride, stocks of major US banks rose in after-hours electronic trading.