William J. O’Neil

William J. O’Neil was an investor, stockbroker, entrepreneur, and author who pioneered data-driven stock research and popularized a systematic growth-investing approach. He founded William O’Neil & Co., created the CAN SLIM investment strategy, launched the market research products Daily Graphs and MarketSmith, and established the financial newspaper Investor’s Business Daily (IBD). He died on May 28, 2023, at age 90.

Key points

• Early adopter of computers for securities research; built one of the first computerized daily securities databases.
• Creator of CAN SLIM, a seven-factor growth-investing system combining fundamental and technical analysis.
• Founder of Daily Graphs (1972) and MarketSmith (2010), tools that bring institutional-style charts and screening to individual investors.
• Founder of Investor’s Business Daily (1984), a national financial newspaper and data platform.

Early life and education

Born March 25, 1933, in Oklahoma City, O’Neil’s early experiences during the Great Depression influenced his financial perspective. He earned a bachelor’s degree in business from Southern Methodist University in 1955 and later served in the U.S. Air Force.

Career and innovations

O’Neil began his financial career as a stockbroker with Hayden, Stone & Co. in Los Angeles in 1958. In 1963 he founded William O’Neil & Co., which developed a computerized daily securities database that tracked tens of thousands of companies—a significant innovation at the time. By age 30 he had purchased a seat on the New York Stock Exchange.

His work emphasized rigorous data collection and pattern recognition, combining quantitative screens with chart-based technical analysis to identify high-potential growth stocks.

The CAN SLIM strategy

CAN SLIM is an acronym for seven traits O’Neil recommended investors use to find leading growth stocks:

• C — Current quarterly earnings per share: strong recent EPS growth.
• A — Annual earnings: consistent multiyear annual earnings growth.
• N — New: recent innovation, product, management, or new highs in price and volume.
• S — Supply and demand: favorable share structure and rising volume.
• L — Leader or laggard: buy market leaders within industries.
• I — Institutional sponsorship: growing investment from mutual funds and institutions.
• M — Market direction: follow overall market trends and timing.

CAN SLIM blends fundamental earnings criteria with technical and market-timing elements to improve stock selection and risk management.

Daily Graphs, MarketSmith, and investor tools

O’Neil launched Daily Graphs in 1972, a weekly publication of stock charts that brought institutional-quality charting and analysis to individual investors. In 2010, MarketSmith evolved as an online platform extending Daily Graphs’ charting, screening, and research tools, integrating CAN SLIM principles into visual and quantitative workflows.

Investor’s Business Daily

In 1984 O’Neil founded Investor’s Daily, later renamed Investor’s Business Daily (IBD). IBD provides market news, data, screening tools, and education focused on growth investing and stock selection. The publication and its digital products have been influential among retail and professional investors.

Books and legacy

O’Neil wrote several widely read investing books, notably How to Make Money in Stocks and 24 Essential Lessons for Investment Success. His work popularized a disciplined, research-driven approach to growth investing and helped democratize tools once available only to institutions. His methodologies remain taught and used through books, seminars, and the platforms he created.