For the second time this week, the Dow Jones Industrials (^DJI -0.25%) posted a decline of 200 points or more. Today's 243-point drop was particularly worrisome, coming as it did on the tail of multiple earnings disappointments as well as a general lack of enthusiasm about the stock market and the prospects for the global economy. Beyond just earnings numbers, a sentiment shift seems to be pointing toward an increased likelihood that a long-anticipated correction may finally be near.

But a few stocks really stood out in hurting the market. DuPont (DD) ended the day down a whopping 9% after big declines in revenue and earnings, coupled with a major pullback in forward earnings guidance, shook shareholders. What was particularly disturbing was that the company hadn't missed analyst estimates in 14 straight quarters, building expectations that DuPont would be able to manage its earnings effectively to avoid surprises like this one.

3M (MMM -0.99%) plunged 4% after making its own cut to its full-year guidance. Shareholders were merciless, as a cut from a range of $6.35 to $6.50 to a range of $6.27 to $6.35 was enough to cause the big plunge. The company used the convenient "slow-growth economy" excuse, which you'll probably hear several more times before earnings season ends.

Finally, Hewlett-Packard (HPQ -0.78%) fell more than 3% on the heels of Apple's (AAPL 0.57%) string of new product announcements. With everything from the anticipated release of the iPad Mini to a full-sized fourth-generation iPad, a smaller iMac, and a new MacBook Pro, Apple is capitalizing on the weakness in the PC market to make advances on all fronts. Judging from the response in HP's stock, investors aren't sure whether the company can adequately answer Apple's offensive.