No man can learn all there is to know about forecasting the trend of stocks in 3, 5, 10, or 20 years but if he is a deep student and hard worker, he learns more and knowledge comes easier after years of experience. I knew more about determining the trend of stocks in 1923 than I did in 1911. Seven more years of experience gave me more knowledge and enabled me to write THE WALL STREET STOCK SELECTOR in 1939 and give my readers the benefit of my increased knowledge. Now, after five more years have elapsed my experience and practical test of new rules have enabled me to learn more of value since 1930. The 1929-1932 panic and what has followed since, gave me valuable experience and I have gained more knowledge about detecting the right stocks to buy and sell. W.D. Gann