6 big banks, 6 big shake-ups

Who's out: Merrill CEO Stanley O'Neal stepped down from his post on Oct. 30. The ousted executive came under pressure after the company took a nearly $8 billion loss on mortgage bets that turned sour. His overtures to Wachovia about a potential merger, without the nod of Merrill's board, however, likely accelerated his decline.

What's shaking: Merrill had begun cleaning house before reporting its massive third-quarter writedown. In early October, the bank replaced its global head of fixed income, Osman Semerci, with David Sobotka, head of global commodities. The company also appointed head of credit risk Ed Moriarty to the newly created position of chief risk officer.

Cause of concern: The bank took a staggering $8.4 billion writedown in the third quarter, most of which was due to a decline in the value of subprime mortgages and complex debt instruments.