There aren't any surefire ways to tell if the stock market, and perhaps the rest of the economy, is about to take a nosedive. That's because millions of people with millions of ideas are involved, so it's an inherently unpredictable system. However, there are certain players in our economy that have a lot more influence and insider knowledge than the rest of us. So when they make a move in unison, you know there's a good chance that something is about to go down.

And that's exactly what's going on with the stock market right now. The people who would stand to lose the most if the markets crashed; the corporate executives and insiders, are all jumping ship and selling their stocks.