As an executive at investment bank Drexel Burnham Lambert Inc. during the 1980s who used high-yield junk bonds for corporate financing and mergers and acquisitions. Michael Milken amassed an enormous personal fortune, but in 1989 he was indicted by a federal grand jury and eventually spent nearly two years in prison after pleading guilty to charges of securities fraud. While he is credited with founding the high-yield debt market, he was banned for life from the securities industry. Nicknamed "The Junk Bond King" in the 1980s, Milken earned between $200 million and $550 million a year at the height of his success. Following his release from prison, he worked as a strategic consultant. This was in violation of his probation, and he was subsequently fined $42 million for these actions. In 1993, Milken was diagnosed with prostate cancer; since then, he has devoted much of his time and resources to the pursuit of a cure for the disease.