Yesterday's plunge in the Dow Jones Industrials (DJINDICES:^DJI) has brought on a predictable flurry of discussion about whether a long-awaited correction may finally be in the cards for the stock market. This morning's follow-through selling certainly supports that notion, as the market ignored a slight increase in existing-home sales and news that housing inventories were at their lowest levels since 2000. However, with Zillow estimating that 2 million homeowners worked their way out of being underwater on their mortgages during 2012, one big overhang holding back consumers may be dissipating, which could point to longer-term bullish prospects for the economy. In the grips of fear, though, the Dow is down 61 points as of 10:55 a.m. EST. Broader markets have fallen a bit more than the Dow, and international markets are responding still more negatively to yesterday's U.S. market sell-off.

Among the Dow's worst performers is Caterpillar (NYSE:CAT), which is down 2%. Yesterday the company reported that global sales in the three months ending in January dropped 4%, marking a second straight monthly decline after sales had risen steadily for more than two and a half years. Although Latin America and the Europe-Africa-Middle East segment improved, sales in North America and the Asia-Pacific region were both down by double-digit percentages. With Caterpillar focusing on those latter markets for growth prospects, it needs those trends to reverse in order to see better share-price performance again.

Elsewhere, Safeway (NYSE: SWY) climbed almost 7% after reporting strong earnings, as net income rose 13%. The grocery retailer's store loyalty program helped the chain boost sales by 1.2% during the quarter, with same-store sales excluding gas purchases rising by 0.8%. Still, the grocery business is extremely competitive right now, and with big-box retailers, organic and health-conscious niche grocers, and traditional rivals all fighting for business, Safeway must continue to fight hard to keep moving higher.

Finally, Groupon (NASDAQ:GRPN) jumped 5.7% after getting a rating upgrade from Piper Jaffray. Although many investors feel the daily-deal play has run its course in the U.S., Piper pointed to strength in international markets as a potential driver for future growth. The company has benefited from increased analyst awareness lately, with many seeming to see the beaten-down shares as a long-term value proposition, given the company's well-known name.