Forecasting the NYSE with the Jupiter-Saturn Cycle | L.H. Weston

[...] Diagram A is designed to show the curve of influence produced on stock market prices by the varying angular distances of Jupiter from conjunction or opposition with Saturn. It will be seen that at 0 years and 0°, which is supposed to represent the time of geocentric conjunction and opposition of the planets, the dotted curve, which is our composite price of stock in the 10-year cycle, starts a little below the mean circle; then late in year 1 when distance is about 18° between the planets it goes to maximum height; then drops low in middle of year 3 at 54°; rises to late in year 5 or 90°; drops soon to a little late in the 7th year at 126°; rises slowly to past the 9th year or 162°; lastly, comes to a little below the mean again at 10 years, 180°, same as at beginning. Then at 180° another 10-year cycle starts and repeats this movement, and so on to eternity. It is thus seen, by the dotted curve in this diagram that Jupiter and Saturn cause maximum and minimum prices in the stock market when their geocentric angular distances between each other are about as follows:

 

Max.    Min.
18°    54°
90°    126°
          162°   180° and 0°

 

This dotted curve shows positively that the planetary influence is what we call harmonic, meaning a wave-like motion, fixed in angular position like the crystals of a snow flake (hydrogen at low temperature) with 2 minor axis that join at 72°, as illustrated by the central part of diagram A." [pp. 35-36]

See also HERE

General consensus within the astro-financial community traces the primary development of modern financial astrology to around the 1920s, when W.D. Gann mentioned a planet for the first time in a 1921 Forecasting Course and Professor J.H. Weston self published his breakthrough work 'Forecasting the New York Stock Market' (manuscript, no binding, 47 pages). Also in the early 1920s Sepharial produced most of his known 'Arcana' or 'Keys' to the markets, though he stated in his advertisements that these systems had been in development since 1898. However Professor Weston represents the earliest application of Fourier Sequences to market analysis, by breaking down component cycle waves and combining them to produce a composite model. 

J.H. Weston was a regular contributor to Frederick White's journal 'The Adept' (e.g. HERE) and also one of the first to propose a 'Decennial Cycle' theory, actually with two different versions of the ten year pattern. The first is his computation based on 50 years of data, of a series composed of 14, 20 and 28 months, called the Venus term and based upon the heliocentric system. The second is a sequence which divides the Jupiter-Saturn cycle into 10 irregular parts, but follows the geocentric system. Professor Weston was a great influence on W.D. Gann, implied by his manuscript being locked in Gann's safe, and he may have been the one who introduced Gann to Fourier cycle theory, providing Gann with the foundation for his 10 year cycle with its multiples.

Reference:
L.H. Weston (1921) - Being a Treatise on the Geometrical or Chart System of Forecasting in which is explained the principles of the art, and, in this lesson no. 1, giving demonstration with the price curve of potatoes in U.S. 

The Adept - The American Journal of Astrology (V20 N10 Oct 1920 - V21 N9 Sep 1921) 

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