Other risks aside from macroeconomic issues and low interest rates include fragile investor confidence on the financial sector, and new regulations that may cause banks to raise further capital and liquidity.
Notably, Moody's 2012 bank ratings downgrades hinged on the assumption that the U.S. government will be reluctant to bail out large financial institutions, were a new crisis to emerge. As regulators continue to hammer out laws to resolve troubled banks, the agency still sees the prospect of ratings pressure.
On the positive side, Moody's says revamped liquidity and a focus on increasing regulatory capital through the crisis puts U.S. banks in a far more stable position in the wake of the crisis.
For more on banks and the Federal Reserve, see how the central bank prepared to buy bank stocks in 2007.For more on Moody's bank ratings actions last year, see the agency's June 2012 ratings bloodbath. Follow @agara2004 -- Written by Antoine Gara in New York