Thus far in 2013, the markets have essentially chugged along quite nicely. Yesterday, the S&P 500 Index (SNPINDEX:^GSPC) rallied to a five-year high on encouraging housing data and unemployment numbers. Today, the index closed at a five-year high -- again -- this time, buoyed by a proposed extension to the debt limit brought forth by Congress on Friday. Still, no matter how many proverbial bones are thrown their way, a handful of stocks manage to plunge. And today's three biggest S&P 500 losers, well, plunge they did.

Abandoning its dietary New Year's Resolution weeks before absolutely everyone else will, Advanced Micro Devices (NASDAQ:AMD) took the cake as today's biggest decliner, falling a crushing 10.2%. As bad as that metaphor was, investors figured that AMD's Tuesday earnings would somehow be worse. The consolation? Today's fall was due almost entirely to rival Intel's (NASDAQ:INTC) uninspiring quarterly performance. Unfortunately for these two companies, they traffic their computer chips in the weakening PC market.

Intel's losses today, easily eclipsed by AMD's, were still significant, at 6.3%. Not only did Thursday's results reveal a 27% fall in earnings and 3% slip in revenue, but there wasn't much optimism to be found in the company's forecasts. Capital expenditures were projected to rise nearly 20% this year, to $13 billion. Not exactly what you want to see as your sales and profits are declining. 

Down 4.1%, Monster Beverage (NASDAQ:MNST) couldn't quite match the declines of its beleaguered index peers in the technology sector, but the energy drink maker did its best. Wall Street figured that an outpouring of recent negativity from Washington lawmakers would be bad for Monster's business. On Thursday, two Democratic senators and one Democratic congressman pressed more than a dozen energy drink companies -- Monster among them -- to justify some of their marketing claims, as well as reveal more of their ingredients. As the largest domestic energy drink player by volume, Monster investors saw all risk and no reward to today's inquiries.

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