There are professional astrologists who've used their trade on the markets. Back in the 90s, Art Campbell--I think that was his name--was one.
And I came across a guy online who used the Bradley Siderograph. It was actually pretty interesting. I posted about it at SI, and he gave me a free sub to his site for awhile. He was a nice guy.
But the trouble with the Bradley Siderograph is that it only indicates possible inflection points. So when one hits, maybe the market--it tracks the DOW--will go up, or down, or nothing will happen.
So it isn't really very useful.