Small cap stocks—those from companies with market values between about $300 million and $2 billion—are famous for their ability to deliver big gains, but they often come with a wild ride. When times are uncertain, these stocks tend to lag behind the giants. Yet, given the right economic backdrop, they're known for staging impressive rallies and catching up in dramatic fashion. If you're an investor hoping to broaden your horizons or spot timely opportunities, understanding the forces behind these catch-up m ...