By the 1980s, Dall??s prot??g?? Lewis Ranieri was at the center of a multitrillion-dollar market in these securities. (Ranieri, immortalized in Michael Lewis??s Liar??s Poker for his gargantuan appetite for both food and risk, is a classic example of a poor kid who acquired his skills not in college but by hanging around smart people in Manhattan.) Collectively, these innovators reinvented the fin