Thomas Kostigen

William Joseph O'Neil (March 25, 1933 – May 28, 2023) was an American businessman, stockbroker, and writer. He founded the stock brokerage firm William O'Neil & Co. Inc in 1963 and the financial newspaper Investor's Business Daily in 1984. O'Neil was the author of books like How to Make Money in Stocks, 24 Essential Lessons for Investment Success, and The Successful Investor, and created the CAN SLIM investment strategy.