This is a fascinating book about the sociology of ideas and, specifically, about information theory. Author William Poundstone explores how Claude Shannon, the major developer of information theory, affected finance, investing and gambling. These activities seem disconnected, but they all rely on managing uncertainty. Like any great idea, information theory attracted major personalities: gamblers, mobsters, academics, economists, traders and people who just wanted to make money. The story weaves through a collection of memorable people (from seventeenth-century mathematicians to Ivan Boesky) to present pertinent mathematical and scientific theories, and to explore how people used them. At times, the connections between events seem strained, but they all come together. This book is encyclopedic, exceptionally informative, and packed with great stories and characters. We enthusiastically recommend it to anyone seriously interested in investing, the sociology of ideas, or gambling. Indeed, read it twice: once for its theories and practical investment advice, and the other to relish its personalities.