Five Dumbest Things on Wall Street: Jan. 9

BofA's Broker Stampede

Bank of America(BAC Quote) CEO Ken Lewis better start wrangling that "Thundering Herd" of brokers he just bought before they stampede right out the door.

The head of Merrill Lynch's brokerage operations, Bob McCann, announced his plans to leave the securities firm Monday, an announcement that came just days after the completion of the company's acquisition by BofA.

McCann, a 26-year veteran of the firm who is said to be popular among Merrill's 17,000 brokers, had led the wealth-management division at Merrill, but saw his responsibilities narrowed in a new lineup set by BofA in October.

On Tuesday, Bank of America named Dan Sontag, a 30-year Merrill veteran who previously served as head of wealth management for the Americas, to fill McCann's vacated spot.

While BofA moved quickly to replace an important stone in what Lewis calls the "crown jewel" of his banking empire, it was not before Wall Street began loudly questioning if the emperor had a firm grasp over his subjects.

"In our view, Merrill's brokerage unit was likely the main attraction for Bank of America in completing the acquisition, and if brokerage attrition picks up, the acquisition becomes less valuable," wrote Stuart Plesser, a banking analyst with Standard & Poor's Equity Research.

Plesser is not alone in fearing a clash of cultures between BofA's buttoned-down bankers and Merrill's hard-charging brokers. Analysts across Wall Street are wondering how long Merrill's rainmakers will stick around while their new bosses in Charlotte cut costs.

Lewis recommended to BofA's board on Tuesday the elimination of bonuses for top executives after shares fell 66% in 2008. We don't want to be in the path of a raging herd of Merrill brokers if Lewis tries to clip their commissions, as well.

Dumb-o-meter score: 75 -- Saddle up Ken! Or kiss your crown jewel goodbye.