In the aftermath of a market decline where 80 million Americans lost between 50-80% of their wealth, it's sometimes hard to tell whose advice you can trust. Still, each day, smart investors around the world choose to trust William J. O'Neil, publisher of Investor's Business Daily and author of the million-plus bestseller How to Make Money in Stocks.

William J. O'Neil is the founder and chairman of Investor's Business Daily and the author of the million-copy best-seller How to Make Money in Stocks. Born in Oklahoma and raised in Texas, William J. O'Neil began his investment career as a stockbroker. He started investing with less than $500, but through continued study, mistakes, and a desire to find out exactly how the stock market really worked, O'Neil realized a 20-fold increase in his own account in 26 months from October 1962 to December 1964. He then purchased a set on the New York Stock Exchange and opened his own investment management and research firm, William O'Neil + Co., Incorporated, at the age of 30. Founded in 1963, William O'Neil + Co. was the first to create a computerized stock-market database, which is used today by over 400 major U.S. institutions across the country, including banks, insurance companies, pension and mutual funds, corporations, and government organizations.