generate a constant monthly gain is the vexatious sentence in the OP. I quite agree with Tabas that trading isn't a pre-determined involvement where you already know what should come out of it. No one can conveniently tell you exactly how much they can make in a month or in a  trade until the trade is executed. It is a give or take thing. To that I say, No! No one makes constant gain trading. Expect loss too.