Alex Ehrlich should be angry. After turning Goldman Sachs into one of the largest and most profitable prime brokerage and securities financing houses in the world during more than 20 years there, he was overlooked for promotion to managing director last year. He resigned from Goldman, leaving many of his loyal staff incredulous that the bank had allowed him to go.

But being angry is not in Ehrlich's nature. Instead, he is energetically setting about building a hedge fund services business to rival the one he developed at Goldman, this time at UBS.