This is the goldmine. McWhirter provides specific rules for forecasting:

To understand why traders are desperate for the one must first understand the "McWhirter Principle."

(first published in 1938), remains a cornerstone for financial astrologers seeking to bridge celestial mechanics with economic cycles. Her core premise is that the major trends of business volume and finance are dictated by the 18.6-year cycle of the North Node as it transits through the twelve signs of the zodiac. The 18.6-Year Nodal Business Cycle

While the Nodal cycle provides the macro view, McWhirter utilized several "secondary factors" that could alter market movement by up to McWhirter's Market Forecasting Techniques - Karen Christino

In the high-stakes world of modern finance, where algorithms process terabytes of data in milliseconds and fundamental analysts dissect balance sheets to the decimal, the idea of consulting the stars seems archaic, if not heretical. Yet, buried in the annals of Wall Street history lies a fascinating, enduring, and controversial methodology: financial astrology. At the forefront of this discipline stands Louise McWhirter, a figure whose work continues to captivate traders nearly a century after its publication.