BofA: Financial Winners and Losers

(Updated with final stock price moves.)

NEW YORK (TheStreet) -- Bank of America (BAC Quote) was among the losers of the financial sector Thursday after the surprising retirement of CEO Ken Lewis was announced late Wednesday.

Bank of America finished lower by 4.2% after the bank said CEO Ken Lewis has decided to retire by the end of the year. BofA said its board would "continue ongoing planning" in order to name a successor by the time Lewis steps down on Dec. 31. Lewis is also leaving his position as a director on the company's board.

Independent research firm CreditSights said that the timing of Lewis' departure was "not altogether surprising" given the heightened scrutiny he and the company have been under for some time. Lewis and BofA have been the target of separate probes by New York Attorney General Andrew Cuomo and House Oversight and Government Reform Committee Chairman Edolphus Towns (D., N.Y.).

"That said, we find it disappointing that BofA was not prepared to name a successor at this time, leaving the nation's largest depository without the smoothest change in leadership," CreditSights said in a research note.

Rochdale Securities analyst Dick Bove argues that the success of BofA is due to "the brilliance of Ken Lewis as a visionary and tactician." Bove adds that Lewis generated the cash flows that allowed his predecessor to make large acquisitions while maintaining the operating disciplines that allowed the bank to "dominate in the sale of multiple financial products."

"No other banker in this country can equal his achievements and yet every banker wishes s/he could," Bove wrote in an email late Wednesday. "Yet despite his successes, he was torn from his post by politicians lacking any of Mr. Lewis' skills and successes. One can only be amazed that our system of governance can be so flawed."