Summary Box: Banks hit 5-year high in earnings

VERY profitable year: Last year, U.S. banks had run their most profitable since 2006. The increase was mainly because banks suffered fewer losses - not because, in more money.

Big banks did well: The Federal Deposit Insurance Corp. said banks with assets of more than $ 10000000000 accounted for most of the climb - a 40 percent increase over 2010, to reach $ 119.5 billion.

SHRINKING loss reserves: banks, especially the biggest ones, set aside huge reserves for possible loan losses in the wake of the financial crisis over. If the losses moderated, the banks could register high profits from the release of reserves.