For all of Wall Street’s unexpected twists during the past year, the markets’ upheaval did produce at least one predictable effect: a string of abrupt divorces between high-ranking executives and the firms they helped lead.

Many top bankers and traders have seen their careers stall amid mounting losses and accusations of managerial failure. The casualty list includes Merrill Lynch’s Stanley O’Neal, Bear Stearns’ Warren Spector, Zoe Cruz of Morgan Stanley and Citigroup’s Tom Maheras.