I saw a documentary on him a while back. He once owned an investment firm and made a boatload of money, but he worked so much and stressed out so much that he almost lost his family and his sanity. He quit and did some other things before coming back into the spotlight, first as the founder of thestreet.com, then a guest commentator on CNBC's Squawk Box (highly recommended for anyone interested in how the real financial world works), then after the SEC starting getting strict on reporting financial news vs recommending stocks they moved him to Ludlow & Kramer show. After about a year of that show, he got his own show Mad Money.