Trading Planetary Eclipses
by Hans Hannula, Ph.D., C.T.A.
Stock market lore has long been filled with claims that planetary motion affects stock and commodity
prices. As most market students who pursue this topic find out, however, many rules and explanations of
what causes tops and bottoms in markets contradict each other about which planets are important and
what could cause these effects. There are relationships, but they differ from what one might find in the
literature of financial astrology. Hans Hannula explains.
In financial astrology, the angles formed between two planets as viewed from the Earth have either
bullish or bearish implications for the market. In astrological jargon, these angles are called aspects. The
angles are measured from a line drawn from the Earth to the sun. When a planet is aligned with the sun, it
is said to be in geocentric (Earth-based) conjunction, or at zero degrees. If the planet is between the Earth
and the sun, it is called an "inferior" conjunction. When a planet is positioned so that the Earth is directly
between it and the sun, it is said to be in geocentric opposition, or at 180 degrees. Similarly, if the planet
is at 90 degrees to the Earth-sun line, the planets are said to be square. Squares are supposedly bearish.
Conjunctions and oppositions are supposedly positive.
But this interpretation is not universally accepted. David Williams, author of Financial Astrology, uses
an aspect-scoring system in which he attributes bullish or bearish influences to each aspect according to
which two planets are involved. For example, he considers the conjunction of Mercury and Earth
positive, but that of Mars and Earth negative. Even with this difficulty, however, financial astrologers
have used aspect rule-based systems to predict stock movements with enough success that they are still
Personal computers have spawned renewed interest in using this approach for trading. First, compute the
time of each aspect between each pair of planets and measure the change in market price some time later.
If prices are up or down over some threshold, say 70% of the cases, record the aspect as bullish or
bearish. If it is under the threshold, consider it insignificant. This gives a scoring table for the aspects.