When the moon is in the seventh house and Jupiter is aligned with Mars, go long oats and sell gold and stocks.

Wood said he started watching the planets because his clients were doing it. About a third of his clients were using astrology before they came to him, he said. Practitioners divine market changes by using mathematical calculations based on planetary movements.

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Chicagoan Norman Winski is another Indiana native practicing financial astrology. He bills himself as an “astro-cyclical consultant” and sells a monthly newsletter called Astro-Trend, along with a set of books and software that incorporates astrology. Winski runs a consulting business for traders and brokers and he has traded for himself using astrology for 13 years.

The biggest traders using astrology are extremely shy about letting their method be known. One broker at the Merc said, “You’d be amazed at the people who are using it. There are some heavy hitters behind the scenes” doing stargazing.

“Some people say, I don’t want to know about it, but as long as it works, it’s OK,” said Merc trader Carolyn Boroden, a recent convert to financial astrology. “Others say, whaddaya, kidding? And others just watch it for a while, and when they see that it works, they start doing it.”