It does but western astrology tends to give out trends and directions as opposed to other forms of astrology

Vedic astrology does both predict and give out trends

Study of astrology is based on planetary position in sky at the time of birth and at time of an event occurrence. since now a days we do have planetary ephemeris which gives planetary position in sky in advance, so we could know when a particular planet aligns with natal planet so that they together create a combination to yield one particular result based on your natal(birth chart) chart

There are 1000s of books in astrology written by sages. One says yes, other say No, few say Yes with Remedies to be preformed. But all astrologers make money!