Investing is risky. No question about it. It's not really all that much fun to be terrified of losing your money. With commodities you can lose more than you invested. Yes, you can lose all or most of your money there, too, although your chances of making it through to the credits are better.
Companies do go into bankruptcy, and high-flyers subside into a state of permanent underperformance.
That's why portfolio diversification is so important. You might as well worry about your neighbor turning into a werewolf. Even if a high yielding Dow stock did hit the skids, you would have three other companies in your Foolish Four portfolio to offset that loss. Below is a table showing the annual performance of the Dow 30 and our three main strategies going all the way back to 1962. The returns are for portfolios started on January 2 and held for one year.