Most of the market's recent zigs and zags are attributable to prognostication about what the Federal Reserve will do with regards to tapering its bond-buying program. The question isn't whether the $85 billion per month program will ratchet down, but when it will happen. Two Fed officials today and yesterday said they thought tapering should begin sooner rather than later. The Dow Jones Industrial Average (DJINDICES:^DJI) didn't much like that, and the index slid 76 points, or 0.5%, to close at 15,177.

Merck (NYSE:MRK) added 2% today after shares in the pharmaceutical company were reiterated at outperform by BMO Capital. BMO Capital also raised its price target on shares to $54, citing a strengthening pipeline. It's the second straight day of strong gains for the stock. Yesterday, shares traded nearly 4% higher on news that a Merck drug achieved impressive results in the treatment of advanced melanoma. 

AT&T (NYSE:T) tacked on 1.7% today, ending with the second-biggest gains in the index. There wasn't anything too substantial driving he stock higher, but AT&T rival Sprint is trying to fetch the highest price from two different bidders, and higher prices there may justify a higher price tag on AT&T. 

Microsoft (NASDAQ:MSFT) slumped 1.7% after data about smartphone usage came out that underlined how much ground the company has to make up for if it wants to truly compete in that lucrative space. As far as mobile operating systems go, Google's Android led the pack with 52% of the share. Apple phones comprised 39% of the market, BlackBerry's share was 5%, and then, finally, came Microsoft, at a mere 3%.

Home Depot (NYSE:HD) lost 3.1%, slipping even as the real estate market is in the midst of a rebound. It's actually possible that the rebound plays into the reason Home Depot fell today: Rather than fix up older places, consumers are starting to buy brand-new homes. Not only that, but if the Fed tapers its spending and allows rates to rise, people may be discouraged from borrowing money to make home repairs.


Fool contributor John Divine owns shares of Apple. You can follow him on Twitter @divinebizkid and on Motley Fool CAPS @TMFDivine.

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