Toward Ecosophy

The classic method is astrology; as J.P. Morgan said, "millionaires don't use astrology, but billionaires do." There are entire schools of trading based on astrology, and there's a secondary market in that once you know stock market astrology, lots of people want to learn it and will pay for the privilege. That said, geomancy would be entirely workable for the same purpose; I don't know of any modern practitioners of market trading that use it, but it was certainly used for financial and economic divination back in the day.