1. Assume the people you will be trading against will be 10/10 in every category. Also assume that they will have so much capital that they can move the market. Assume that they will do so with the specific intent of taking all your money.
2. Count your lucky stars.
Divide item 2 by item 1.
Some people are having success with it.
There were a lecture and a workshop at OHM 2013 "Building A Trading Robot With Open Source Tools", perhaps you can find a recording (the OHM 2013 website appears to be down at the moment).