I have some friends that have made a lot of money playing poker. The analogy is very good. But, in poker you have to be willing to deal with much bigger ups and downs than what I had to deal with. You can hit a bad streak and it can hurt - even if you are in fact a really skilled player and do in fact have an edge.
With my program I didn't really have bad streaks because my P&L was averaged out over thousands of trades per day.
Not always true. There are plenty of ways to minimize risk.
I played HUSNGs for a living for several years, and I could play three tables at a time (about 9 games per hour) with a 60% winrate. That's incredibly low variance--my graph over the long-term was better than a 45 degree incline.
With my program I didn't really have bad streaks because my P&L was averaged out over thousands of trades per day.