From an astrological standpoint, predicting the events and fortune of a single company or a line of business, is not that difficult. The stock market, though, is a much more complicated thing.
To use astrology in the analysis of a company, it is necessary to be able to erect a probable horoscope for its birth, or its latest major change of structure or ownership. With that horoscope, analysis and predictions are extracted in pretty much the same way as with personal horoscopes.
In predicting the general development of a whole line of business, such as banking, shipping, media or medicine, a horoscope is not needed. Instead, the planetary movements through the zodiac are interpreted, without the need for a particular starting point to compare them with.