The unrepentant bullishness was good while it lasted. Following yesterday's buying bonanza that sent the Dow Jones Industrial Average (^DJI 0.56%) 308 points higher, today, Wall Street took a deep breath and decided to cash in some gains. The selling also came on the heels of a Federal Reserve meeting that indicated its "loose money" bond-buying program may come to an end in 2013. The Dow fell 21 points, or 0.16%, to close at 13,391. 

Thursday's biggest Dow gainer was Merck (MRK 0.44%), adding 2.4%. The gains come a day after the FDA acknowledged the newest New Drug Application (NDA) that Merck submitted for ezetimibe and atorvastatin tablets; these two drugs are used to combat high cholesterol. 

UnitedHealth Group (UNH 1.61%), however, was the most notable Dow laggard, falling 4.7%. Deutsche Bank downgraded the stock to a "hold" from "buy," sending the stock tumbling. The investment bank believes that premium increases may not adequately cover increases in medical costs this coming year, and could impact the company's profitability. 

Outside of the Dow, Chinese solar company First Solar (FSLR 0.43%) was the beneficiary of a change in analyst opinions, jumping 7.6%. S&P Capital IQ still rates the stock a "sell," and sees "significant competitive pressures." Still, First Solar investors applauded the fact that the company is no longer a "strong sell." Improvement is improvement, I guess. 

Shares in legendary American automaker Ford Motor (F 0.66%) also caught a break today, trading 2% higher at the market's close. New U.S. Ford vehicle sales rose 1.9% in December from the year before, selling 21% more than the company did in November. Growth was driven by the demand for more fuel-efficient vehicles, like the Ford Focus and Ford Fiesta, which saw sales spike by 58% and 52%, respectively.