William O'Neil has been the authoritative voice of investors and stockbrokers all across the United States ever since he formed William O'Neil & Company in 1963; today the company works exclusively with institutional investors. The founder of Investor’s Business Daily and the inventor of the CAN SLIM investment stratagem – which limits losses to a 7% mark and outperforms even the S&P 500 -- O’Neil is a much sought after lecturer and mentor for up and coming stockbrokers and those who need a bit of extra help to get to their next levels of market achievement.

William O'Neil’s career in the fiscal landscape of America began in 1958, when he joined the firm of Hayden, Stone & Company as a stockbroker. Over the course of his initial tenure with the firm, he researched the intricacies of stock trading and also enlisted the help of the earliest available computers to model the successes and failures of stocks. He tabulated stocks all the way back to 1953 to track their developments, successes and also failures.

The fruits of this labor was the development of the CAN SLIM investment strategy, which is actually an acronym standing for current earnings, annual earnings, new product or service – all of these make up the CAN portion – followed by supply and demand, leader or laggard, institutional sponsorship, and finally market indexes, all of which denote the SLIM part.

O’Neill perfected his stratagem to such an extent that he managed to pinpoint consistently well performing stocks simply by ticking them off against his check list. This system has become so successful that it even outperformed the S&P 500. The secret to his success is the loss limitations which are – without exception – set at about 7% or slightly above, preventing the staggering investment losses of recent years.

Following his own guidelines, William O'Neil’s career at Hayden, Stone & Company took off and after only five years, in 1963, he left the firm to start his own investment management and also brokerage firm, known as William O'Neil & Company. At the scant age of 30, he bought himself into the New York Stock Exchange and plied his trade with stellar success.

10 years later, in 1973, O’Neil pioneered O’Neil Data Systems, a company that worked with cutting edge software and hardware components to publish databases. The company is still in business today. Nine years after that, in 1984, the groundwork for Investors Business Daily was laid and suddenly the Wall Street Journal, a publication which thus far had remained unchallenged, had stiff competition.

Over the course of his career, O’Neil veered away from private investors and instead began working with institutional investors on a national level. As of 2009, William O'Neil & Company work with roughly 400 investors and continue to follow the precepts of extensive market analysis to identify solid stocks and limit market losses.