2009 Reprint of the original 1949 edition. Paperback. 149pp. William Delbert Gann (6 June, 1878 - 14 June, 1955) also known as W. D. Gann, was a finance trader who developed the technical analysis tool known as Gann angles. Gann market forecasting methods are based on geometry, astrology, and ancient mathematics. Opinions are sharply divided on the value and relevance of his work. Gann wrote a number of books on trading, the classic text being 45 Years in Wall Street. Gann has developed a very faithful group of followers and adherents.