Just to put that $600M fine in perspective: According to the US Government, Drexel paid Michael Milken $296M in 1986 and $550M in 1987. He avoided a heavier jail term by pleading guilty to the aforementioned securities fraud charges in exchange for the government dropping the more serious charges of insider trading and racketeering, (a very good deal for him, I would say). In addition, he was banned for life from working in the securities industry.

Whilst it is true that he also received a 10 year jail sentence in 1990, note that this was reduced to two years plus three years probation in 1991.

Upon his release from jail, Michael Milken began working as a management consultant but came into conflict with the SEC, who deemed that he was in violation of parole.