Decennial Pattern for 2013

Larry R. Williams: The Right Stock at the Right Time, p. 11

In his book Tides and the Affairs of Men (1939), Edgar Lawrence Smith presented the idea of a ten-year stock market cycle. Smith's theory resulted from combining two other theories, Wesley Mitchell's 40-month cycle theory and the theory of seasonality. Combining these two periods, Smith theorized that there must be a ten-year, or 120-month, cycle. 

This would result from ten 12-month, annual cycles and three 40-month cycles coinciding every 10 years. When Smith investigated prices more closely, he found that indeed there appeared to be a price pattern in the stock market that had similar characteristics every ten years. This pattern has since been called the decennial pattern.

Smith used the final digit of each year's date to identify the year in his calculations. He termed the years 1881, 1891, 1901, etc., as the first years; 1882, 1892, etc. are the second; and so forth. 

"The 10-year cycle continues to repeat over and over, but the greatest advances and declines occur at the end of the 20-year and 30-year cycles, and again at the end of the 50-year and 60-year cycles, which are stronger than the others." 

W.D. Gann (1954): Master Stock Market Course, p. 224