After yesterday's 300-point move higher, the Dow Jones Industrial Average (^DJI 0.28%) was quite calm for the day, and ended the trading session down 21 points. It was a light day for economic news but, while ADP announced that 215,000 new jobs were created in December, the Department of Labor reported that 10,000 more American's claimed first-time unemployment benefits last week, more than the prior seven-day period. The total number of new claims hit 372,000, when economists were expecting only 362,000.

Tomorrow, investors will know more about the health of the job market when the Labor Department releases its official unemployment numbers for the month of December. And then, starting Tuesday, Alcoa (AA) will officially kick off earnings season.  

Getting back to today, the Dow closed the day at 13,391, down just 21 points, or 0.16%. Of the 30 stocks that make up the Dow, 17 of them ended the day in the red. This afternoon, I explained why UnitedHealth (UNH 2.16%), Wal-Mart (WMT -0.24%), and Microsoft (MSFT -1.24%) were in the red, and three of the index's biggest losers; to read about those companies, click here. Or to read about three of today's biggest winners, which were Merck (MRK 0.22%), Caterpillar (CAT -0.63%), and Alcoa, continue reading below.

So why were they higher?
Shares of Merck moved higher by 2.39% today, after a late announcement on Wednesday stated that the company had resubmitted a drug application to the FDA for a new combination of drugs aimed to fight cholesterol. The new drug is a generic version of Lipitor and a medication Merck calls Zetia. Lipitor was the top-selling drug of all time, and this new version of a cholesterol-fighting drug could be even better for patients, because Zetia adds in a cholesterol-blocking aspect. The Food and Drug Administration should have a decision on the new drug during the first half of the year. 

Both Caterpillar and Alcoa saw their shares increase by 0.96% and 0.89%, respectively, today. The two companies both had a lot riding on the fiscal cliff and the overall health of the economy, so seeing a solution to at least part of the U.S.'s fiscal problems helped give the two companies a boost. But, today, Caterpillar was upgraded by analysts at the ISI Group, which likely gave additional support to the heavy-machinery manufacturer. Alcoa, as I mentioned above, will kick off earnings season on Tuesday, and today's upward push could be some traders buying shares before that announcement.

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