The Bradley siderograph was developed in the 1940's by Donald Bradley to forecast the stock markets. Bradley assigned numerical values to certain planetary constellations for every day, and the sum is the siderograph. It was originally intended to predict the stock markets. William Eng, a noted technical analyst, singled out the Bradley as the only 'excellent' Timing Indicator in his book, "Technical Analysis of Stocks, Options, and Futures" (source: Astrikos).

List of Bradley Turn Dates for:

Peter Eliades of "Stock Market Cycles" wrote, "The indicator was devised in the 1940s by Donald Bradley. He assigned numerical values to the position of planetary constellations for each day and used the sum of those calculations to draw a siderograph, the prefix "sidero-" in this case standing for stars or constellations." Eliades also wrote "Theoretically, the dates of the turns in the Bradley are more important than the actual magnitude of the moves, but the recent indications of turns have been eerily accurate."