Citigroup and Goldman Sachs face a significant exposure to further write-downs, according to an industry report.
The Bank of America has warned that the two investment giants are likely to feel further shockwaves from the credit crunch.
The collapse of the sub-prime mortgage market in the US in the second half of last year has rocked major financial institutions.
It has already prompted Citigroup to write-off $11 billion and part company with its chief executive.
Further woes could be on the horizon, as the price of debt-backed securities has fallen significantly since the fourth quarter of last year.
"Even though exposures stand at smaller levels, the larger price declines and lack of offsetting fee income imply larger potential write-downs than during the third quarter of last year," an extract of the report, seen by Reuters, said.
The ramifications of the credit crunch have reached beyond investment banks, with the US economy now facing the threat of recession.
The Federal Reserve Bank has responded by slashing interest rates by 1.25 per cent since the turn of the year in a bid to avoid that fate.
