The Dow Jones Industrial Average (DJINDICES:^DJI) closed the day down 21 points, or 0.14%, after having risen as much as 114 points earlier in the session. The Dow now sits at 15,499, while the S&P 500 lost 0.01% and the Nasdaq increased by 0.27% today. Stronger-than-expected jobs number from ADP for July at 200,000 and a preliminary second-quarter GDP number of 1.7% gave investors the confidence to move stocks higher this morning, but, unfortunately, the positive feelings wore thin by the end of the day.

Of the Dow's 30 components, 17 closed lower today while only 12 moved higher. This afternoon, I highlighted why three of the losers -- IBM, American Express, and Verizon -- were moving into the red. Now, let's look at three others.

Despite the 10-day grounding of a Qatar Airways 787 coming to an end today, shares of Boeing (NYSE:BA) were lower by 0.6%. One reason for the decline may have been U.S. Defense Secretary Chuck Hagel's promise today to cut the Pentagon's overhead by almost $40 billion during the next decade and lay the groundwork to cut compensation by $50 billion. The Pentagon needs to cut $500 billion over the next 10 years as part of the sequestration, which comes on top of the already $487 billion in cuts already under way. The nearly $1 trillion in cuts will surely have an impact on defense contractors like Boeing that not only provide new aircraft but have servicing contracts to help maintain the planes once they have been delivered.  

Shares of Alcoa (NYSE:AA) declined 1% on very little news pertaining directly to the company. Year-to-date shares are down 8.41% as the company has dealt with high supply and low demand in much of the world. But with news coming from China last week that the government wants business's to reduce supply of key materials, one of which was aluminum, investors should expect to see aluminum price stabilize and Alcoa to realize better margins in the future. Today's decline, though, indicates that investors will believe Alcoa can turn a profit again after seeing it, not just on the hopes that it will happen.

Shares of General Electric (NYSE:GE) slid lower by 0.45% after Comcast (NASDAQ:CMCSA) reported quarterly earnings this morning that beat on both the top and bottom lines. Comcast was expected to post revenue of $16 billion but had sales of $16.3 billion and earnings per share of $0.65 while analysts were looking for $0.63 per share. The results were boosted by a 9% increase I n revenue from NBCUniversal, which produced $6 billion in sales when analysts expected just $5.75 billion. The reason General Electric may have declined on this news is that Comcast bought GE's 50% stake in NBCUniversal for $16.7 billion back on March 19. After seeing today's results, GE investors may be feeling that the price was too low and that they didn't get quite as good of a deal as they initially thought. 

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Fool contributor Matt Thalman has no position in any stocks mentioned. Check back Monday through Friday as Matt explains what caused the Dow's winners and losers of the day and every Saturday for a weekly recap. Follow Matt on Twitter @mthalman5513

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