Predictably Irrational Predictably Irrational Predictably Irrational: The Hidden Forces That Shape Our Decisions is a 2008 book by Dan Ariely, in which he challenges readers' assumptions about making decisions based on rational thought. Ariely explains, "My goal, by the end of this book, is to help you fundamentally rethink what makes you and the people around you tick. I hope to lead you there by presenting a wide range of scientific experiments, findings, and anecdotes that are in many cases quite amusing. Once you see how systematic certain mistakes are—how we repeat them again and again—I think you will begin to learn
Greed and fear investors are greedy. To calculate this index, a computer takes an equal-weighted average of those seven indicators. Greed and fear Greed and fear refer to two opposing emotional states theorized as factors causing the unpredictability and volatility of the stock market, and irrational market behavior inconsistent with the efficient-market hypothesis. Greed and fear relate to an old Wall Street saying: “financial markets are driven by two powerful emotions – greed and fear.” Greed and fear are among the animal spirits that Keynes identified as profoundly affecting economies and markets. Warren Buffett found an investing rule in acting contrary to such