Wall Street seems to be taking turns paying attention to global economic concerns and company-specific earnings news. Yesterday, the stock market responded very well to positive earnings news, but today, potential problems seem to have come to the forefront. At the close, the Dow Jones Industrial Average (INDEX: ^DJI) fell 83 points to 13,033, while the S&P 500 lost about 0.4%.

Even on a down day, though, a few Dow stocks bucked the trend and posted gains. Let's take a closer look at what's behind the moves in three Dow components today.

Hewlett-Packard (NYSE: HPQ), up 0.9%
Sometimes, stocks move not because of a company's good news but rather because of a rival's bad news. That may be what happened with HP today, after IBM's (NYSE: IBM) report last night raised concerns about some of Big Blue's business segments.

Some analysts pointed to weaker-than-expected results in IBM's hardware and IT consulting areas. As HP tries to figure out the right mix between its strength in hardware and its attempts to expand into higher-margin areas like consulting, any vacuum caused by IBM's weakness represents an opportunity for HP to exploit. Whether HP succeeds in doing so will determine the company's direction in the years to come.

Caterpillar (NYSE: CAT), up 0.8%
Lately, Caterpillar has been very sensitive to cracks in the global economy. But overnight, the company got some good news that should help it grow regardless of macroeconomic factors.

The Chinese Ministry of Commerce gave Caterpillar permission to buy mining-equipment maker ERA Mining, which should allow the proposed deal, valued at up to $886 million, to go forward. The acquisition should further boost Caterpillar's presence in the emerging Chinese economy, although it will continue to face competition from rivals including Hong Kong's Sany Heavy International Equipment.

Pfizer (NYSE: PFE), up 0.6%
Identifying a broad-sweeping strategic vision for a company is always challenging. But when you finally get to execute on that vision, it's almost always good news.

Pfizer is reportedly close to following through on its promise to sell off its infant-nutrition business to Nestle. Earlier this year, Pfizer solicited bids for the unit, which attracted attention from both Nestle and other competitors, including a joint bid from Mead Johnson Nutrition and Groupe Danone. The sale, which would be likely to bring between $9 billion and $10 billion, will allow Pfizer to move forward with a stronger focus on its pharmaceutical business -- and boost its future prospects at the same time.

Stay focused
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