Stocks closed out a volatile week with losses on Friday, after the International Monetary Fund revised U.S. annual growth estimates downward. While maintaining the 1.9% GDP growth figure for the current year, the IMF lowered its outlook for 2014 from an already-unimpressive 3% to a mere 2.7%. That was enough to ding the Dow Jones Industrial Average (INDEX: ^DJI), which tumbled 105 points, or 0.7%, to close at 15,070. Verizon (NYSE: VZ) stock resisted the broad market declines, as a policy announcement from the executive branch caught the ears of shareholders. 

Verizon investors were understandably wary of government initiatives affecting the industry this week in the aftermath of the NSA surveillance scandal. But today's presidential memorandum calling for the federal government to make more of its wireless spectrum available to the private sector was a much-welcomed message. Verizon itself applauded the memo in a press release, and so did investors, as the stock added 0.9%.

It says something about the bearishness of Friday's market that Merck (NYSE: MRK), advancing just 0.1%, merits mention as one of the Dow's top performers. As one of only four advancing blue chips, Merck shares ended barely in the black, as the company scales back on its research expenses. Cutting R&D isn't always a good thing in research-heavy industries like pharma, but smarter spending is always better than more spending, and Wall Street seems to think Merck's planned cutbacks streamline intelligently. 

Chemical giant E.I. du Pont de Nemours (NYSE: DD) lost 2.2% today as a Bank of America analyst downgraded the stock from buy to neutral. Here, DuPont is somewhat a victim of its own success: With the stock's solid performance thus far this year, there aren't many visible catalysts on the horizon justifying that continued trend. The downgrade even said broad economic growth would be needed to justify a buy rating, which, according to the IMF, seems pretty unlikely.

Another victim of analyst views and the largest laggard in the index today, American Express (NYSE: AXP) shares ended 3% lower after a downgrade from overweight to equal weight from Barclays. Citing an earnings multiple that's expanded in recent years, Barclays thinks the business has also matured, essentially insinuating that the stock's gotten more expensive while the potential for growth diminishes.

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Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter @divinebizkid and on Motley Fool CAPS @TMFDivine.

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