The planets have been used as a market timing tool for many years. In the 1940’s an American astrologer Donald Bradley developed a technique for combining the planets into a single line calculation that he hoped would indicate the major highs and lows for the year in the U.S. Stock Market.
This he named ‘The Bradley Siderograph’
The details are published in his book 'Stock Market Prediction' subtitled 'The
Planetary Barometer and How to Use It' available from Llewellyn Publications.
Bradley for U.S. Stocks 2004
The basic formula for the calculation follows. You will see that it is very time consuming to do by hand but there are several computer programs that are
available that will even allow you to change Bradleys formula, so that you can
weight the inputs that you feel are the most relevant.
Bradleys basic formula is this, for every planet, measure the distance between that planet and every other planet (excluding the Moon), and see if it's within a 15 degree orb of a Conjunction, Sextile, Square, Trine, or Opposition. If so it is given a weighted value all depending on the aspect and it's distance from exact. Squares and oppositions are minus, sextiles and trines are plus, conjunctions have different weightings depending on the planets involved.
When there is an aspect within orb, take the distance between the two planets (in degrees), subtract the number from 15 and then divide the result by 15, next multiply the result by 10.
An aspect which is exact gets a value of 10 and 0 if at a 15 degree orb. The weightings increase as the aspect becomes more exact.
This calculation is done for 36 planetary combinations, excluding the Moon.
The 36 combinations are separated into intermediate and long term cycles, with the 10 combinations of Jupiter through Pluto considered the long term, the other 26 represent the medium term cycles.
Next add the sum of the declinations of Venus and Mars, assign a positive value for northern declinations, negative for southern declinations. Add the values for both Venus and Mars and divide by two.
Add together all the long-term weights for the 10 long term cycles, (divided by two), and multiply this number by 4. Then add all the weights for the 26 intermediate term cycles and the Venus and Mars declination and this final number is the Siderograph on any one day.
W.D. Gann