IBD has an amazing system to gauge growth stocks--companies that are growing in earnings per share (and other factors), which cause its stock price to go up. I don't use IBD's system exactly, but the system I've developed is based on their model. To make a long story short, these guys know what factors cause a stock's price to skyrocket (double, triple, and more). Using this website's CAN SLIM factors, I've been able to catch more than a few stocks during huge price moves. I can't recommend them enough, particularly if you're strong in technical analysis like me, but weak at fundamental analysis. I just look for stocks with the highest ratings (they have their own proprietary ratings system) and use my technical analysis skills to time my buys and sells.