Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

The Dow Jones Industrial Average (^DJI -0.11%) sure hasn't been very consistent this week. After roaring 300 points higher in its first three days of trading, the blue chip index nearly gave up its impressive gains, losing 225 points in the last two days. Wall Street's mood swing was most apparent in the last few days of trading: After surging on Wednesday following the Federal Reserve's decision to continue buying $85 billion in assets per month, markets toned down their euphoria. With worries about the debt ceiling swirling, the Dow shed 185 points, or 1.2%, ending at 15,451.

Pfizer (PFE -0.19%) adding just 0.5% was, sadly, today's top Dow performer. The health-care sector was the strongest area of the markets Friday; it lost just 0.3% as a whole. Pfizer, in particular, with its 3.4% dividend, may be shining, as bond yields fell again today, giving income investors a dearth of great places to park their capital. With 1-year Treasuries paying out a whopping 0.11%, it makes all the sense in the world to look to dividend-paying equities for a decent income stream. 

Coca-Cola (KO 1.50%), too, pays a nice little dividend, to the tune of 2.9% per year. Logging 0.2% gains on the day, Coke's stock was one of just three to advance in the 30-stock index. Coca-Cola's most famous investor, Warren Buffett, said today on CNBC that he believed the market to be more or less "fairly valued" at current levels, adding that Berkshire Hathaway was "having a hard time finding things to buy" right now. He also said that any decision to not lift the U.S. debt ceiling would be "pretty damn dumb."

On the losing side of the Dow, Microsoft (MSFT 0.37%) shed 2.5% as a Stifel analyst maintained the firm's hold rating on the stock, citing the company's ambitious desire to turn itself into a device-based company. That will prove to be an expensive initiative, and one that Wall Street clearly isn't confident Microsoft can pull off. If the tech giant can make that vision a reality, though, the result could be a huge boon to shareholders, who will watch with interest as the new Surface tablets hit store shelves on Monday. 

Lastly, Caterpillar (CAT 0.07%) shares were the weakest in the index today, dropping 3.4% after publicly revealing that sales at Caterpillar dealerships around the world fell 10% in the last three months. Of particular concern is the Asia-Pacific region, which saw sales slump 30% in the period, as mining fizzled.