The S&P 500 booked a strong holiday-shortened week last week, rising 3.1% to 1109.17, as sovereign debt concerns, which have roiled the market this year, took a back seat to encouraging data on the U.S. economic recovery.

Pops and drops
Here are the five biggest S&P 500 upticks and five biggest S&P 500 drops of last week (measured Friday close to Friday close):

Winners on the week:


Percentage Gain on the Week

Smith International (NYSE:SII)


Cliffs Natural Resources


Whole Foods Market (NASDAQ:WFMI)




Iron Mountain


Source: Capital IQ (a division of Standard & Poor's).

Losers on the week:


Percentage Loss on the Week



FMC Technologies


Apollo Group (NASDAQ:APOL)




Pulte Homes (NYSE:PHM)


Source: Capital IQ (a division of Standard & Poor's).

A closer look
Shares of Smith International got a boost after it was reported that the company was in advanced talks to be acquired by oilfield services titan Schlumberger. The weekend brought confirmation that Schlumberger would buy Smith International in an all-stock transaction for $10.6 billion.

NVIDIA reported better-than-expected fourth-quarter earnings last week, but investors sold shares on concerns the company is moving away from its core business of graphic chips to high-performance computing and mobile chips. The shift was reflected in the quarter as the company's chipset business declined 19%. But some analysts see the recent pullback as an opportunity for investors. My fellow Fool Anders Bylund says the company is far from dead, and that once NVIDIA sorts out some manufacturing issues it will have a new technology platform.

Shares of Dell fell last week as the computer maker continued to struggle with balancing growth with profits. The company's latest quarter showed that discounts used to spur sales cut into profits. The acquisition of Perot Systems also contributed to the decline. Although Dell is "strategically committed" to its consumer business, recent results show competitors continue to be better able to capitalize on consumer demand. Anders suggests the cure to Dell's ills is exiting the consumer market like IBM did.

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Fool contributor Jennifer Schonberger does not own shares of any of the companies mentioned in this article. You can follow her on Twitter. Apollo Group is a Motley Fool Inside Value selection. NVIDIA and Whole Foods Market are Motley Fool Stock Advisor recommendations. The Motley Fool has a disclosure policy.