Selling all of your stock just before the market falls, and buying shares just before the market rises, is a brilliant strategy. If you could really do it, you would have bragging rights among your friends. And if you could repeat the feat over and over again, you would be fabulously rich – a true stock market wizard.

But the ability to trade like that is rare, if it exists at all. Without question, it’s so hard that the vast majority of professional traders can’t do it, as countless studies have shown.