Efficient market theorists contend that markets are random and thus not predictable. With the publication of Trading Against theCrowd, however, noted author, economist, and professional trader John Summa convincingly shows that investor sentiment can be incorporated into profitable stock and stock market trading systems. In this groundbreaking book, Summa explains how to use popular gauges of crowd psychology, such as put/call ratios, option-implied volatility, short sales, investor surveys, and...