Wall Street trader and author W. D. Gann's third book, first published in 1930, is the follow-up to his acclaimed 1923 publication Truth of the Stock Tape (1923). It aims to provide traders and investors alike with seven more years of Gann's own experiences—including mistakes made and losses incurred—by offering further tried and tested rules and methods that will help traders to study and learn how to select the proper stocks to buy and sell with a minimum of risk.