The latest Fortune includes an Allan Sloan column urging investors to avoid overreaction to market swings:

What should you do with your investments if you hear that the Dow has
suddenly dropped 1,000 points in 20 minutes? Or that euro-panic has sent
stocks swooning? The right answer should be “nothing.” Because if you
have to worry about a 1,000-point Dow drop ruining your life, your
problem isn’t the Dow. It’s that you’re not running your financial life
properly.

Even on a larger scale, doing nothing often makes more sense than doing “something,” as Thomas Woods recently explained to Carolina Journal Radio.