ThinkOrSwim has had a feature like this called ThinkAI for many years. Personally, I think it's not better than random. Years of thinking and ruminating and le

ThinkOrSwim has had a feature like this called ThinkAI for many years. Personally, I think it's not better than random. Years of thinking and ruminating and learning (and investing) on the subject has left me solidly in the "random walk" camp. At any given point, a stock is equally as likely to go up or down. There's a small upward bias in the market (greater than inflation), and I reason that it's the premium offered over debt to take the higher risk of equity. If you plot number of consecutive up-days and down-days, it's a normal distribution, skewed to the right, and with fat tails. That said, my own belief and experience suggests that I can consistently press a small edge, which is why I gravitate towards options and futures (highly leveraged, high notional value). I don't think that would be possible without a "Portfolio Margin" account.