Product Details

• Amazon Sales Rank: #38397 in Books
• Published on: 2006-09-19
• Original language: English
• Number of items: 1
• Binding: Paperback
• 400 pages

Customer Reviews

Inside Info on How the Market Got Beat
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.

Review
I liked the historical background to the Kelly formula, melding the criminal and academic influences that proposed and applied the formula.

However it was sad in a way to see how Shannon's creative genius seemed to be dampened once he began his stock market meddling, indeed it could be said that the principle characters wasted their lifes in the pursuit of money. I guess the book could , I believe unintentionally, be seen as a warning for those who wish to engage in get rich quick schemes.

Kelly formula for calculating investment bets
I picked up this book because Mohnish Pabrai, the author of The Dhandho Investor, recommended it. The author describes the Kelly Formula that was developed by John Kelly at Bell Labs in New Jersey and applied by the individuals featured in the book. The formula calculates the optimal fraction of one's bankroll to bet on a favorable bet.

Edge/Odds = Fraction of one's bankroll to bet each time

For example, if you have a 50% chance of winning $100, and 50% chance of losing $50, how much do you bet? According to the formula, your edge = (50% x $100) + (50% x - $50) = $25. The odds are what you win, which in this case is $100. So the Kelly Formula is $25/$100 = 25%. This means that under this scenario, you bet 25% of your bankroll.

This is an interesting book and I recommend it to other readers.

- Mariusz Skonieczny, author of Why Are We So Clueless about the Stock Market? Learn how to invest your money, how to pick stocks, and how to make money in the stock market