The Dow Jones Industrial Average last week ended up pretty much where it had been a little more than a week earlier. A rousing 200-point rally on Wednesday mostly made up for the distressing 200-point selloff of the previous Friday.

The Dow plummeted nearly 800 points a few weeks ago -- and then just as dramatically rocketed back up again. The widely watched market indicator is down 7% from where it stood in April and up 59% from where it was at its 2009 nadir.

These...