Inside the book Greenblatt updates and expands upon the research findings from the original books, including data and analysis covering recent financial crises and model performances. In a straightforward and accessible style, the book explores the basic principles of successful stock market investing and then reveals the author's time-tested Magic Formula strategy: long-term investment designed to help investors buy a group of above-average companies but only when they are available at below-average prices. The formula is a wonderful strategy for that portion of your portfolio that you choose to invest in the stock market. In fact, this formula remains one of your best options. How much to invest in the stock market, however, is a very personal decision that should be partially based on your ability to withstand short-term negative price movements.