William  O'Neil

William O'Neil

Formal First Name
1933 - present

William O’Neil is the Founder of William O’Neil + Company, a world-class brokerage firm based in Los Angeles, California. He is recognized for being one of the first investors to integrate computers into his research and investment decision-making. He was commended for his efforts in developing a system to help jump-start the American economy. He used his years of experience in economic and business research and his massive historical database to fill a daily information gap that existed for the individual investor.


  • O'Neil started his career as a stockbroker at Hayden, Stone & Co. in 1958, where he developed an investment strategy that made early use of computers.
  • He invented the CAN SLIM strategy while at Harvard Business School, a bullish formula for determining which stocks were likely to grow.
  • He bought a seat on the New York Stock Exchange when he was only 30 years old, becoming at that time the youngest person ever to hold a seat on the exchange.
  • His fascination with the securities market led him to develop his own computerized study of what made stocks successful.
  • He pioneered and developed the use of historical precedent to analyze equities in tandem with fundamental and technical analysis
  • He created his own investment discipline, the O’Neil Methodology, focusing on the trends and patterns of stocks as they become top performers or underachievers.
  • In 1971, he summarized, adapted, and published his findings as The Model Book of Greatest Stock Market Winners, which was the basis for the OM.
  • In 1972, he copyrighted the unique format he had created to capture all the relevant information he needed to make an investment decision about a stock, which he called a Datagraph™.
  • To help provide individual investors with charts and information for their investment research, he founded Daily Graphs, Inc. 
  • Realizing the need to deliver his time-sensitive information ahead of the competition, in 1973 he founded O’Neil Data Systems, Inc.
  • He designed and launched Investor’s Daily in 1984—later renamed Investor’s Business Daily®—, the first national Business newspaper to compete successfully with The Wall Street Journal.
  • Some of his investing influences include Bernard Baruch, Jesse Livermore, Gerald M. Loeb, Jack Dreyfus, and Nicolas Darvas.



  • Named one of the Top 100 Business Luminaries of the Century by TJFR Group and MasterCard International.
  • Featured in the book Market Wizards by Jack D. Schwager in 1988.
  • Received the Classic Award of Recognition from the AeA in 2002.
  • The Stock Trader’s Almanac devoted its 37th edition to him in 2004.
  • Received the prestigious Spirit of Lincoln Award from the Lincoln Club of Los Angeles in 2005
  • Named one of the Most Influential People in Los Angeles by The Los Angeles Business Journal in 2016