James J. McDermott Jr. was the former CEO and chairman of Keefe, Bruyette & Woods.
He was arrested and charged with insider trading in December 1999 by federal authorities.
McDermott had revealed details about an upcoming merger in 1997 to his lover, Kathryn Gannon.
McDermott's lawyers blamed his lapse in judgment on alcohol, depression and family problems.
Although an appeals court overturned McDermott's conviction in 2001, saying his mistress had been unfairly portrayed as a prostitute, McDermott decided against a new trial and instead pleaded guilty to one charge of insider trading.