After another volatile week, the S&P 500 closed out last week nearly flat, up 0.16% to 1,089.41. However, the index clocked the worst performance for the month of May since 1962, losing 8.2%. Last week -- like the entire month -- was dominated by fears surrounding the debt crisis in Europe and the implications for the global economy and U.S. economy.

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

Sprint Nextel (NYSE: S)


NetApp (Nasdaq: NTAP)


SanDisk (Nasdaq: SNDK)


Titanium Metals


Cliffs Natural Resources (NYSE: CLF)


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

Losers on the week:


Percentage Loss on the Week

Diamond Offshore Drilling (NYSE: DO)


Baker Hughes (NYSE: BHI)


Monsanto (NYSE: MON)


DeVry Inc


Smith International


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

A closer look
Overall there wasn’t a great deal of company-specific news that drove individual stocks, although there a couple of significant movers. One bright spot last week was NetApp; shares of the technology storage equipment and data software company rose after reporting fiscal fourth-quarter results that trumped analysts’ estimates. The company also issued a stronger-than-anticipated outlook on strong demand for its storage equipment, as companies update their data centers and upgrade their antiquated technology infrastructure after putting off those purchases during the recession. NetApp’s results are a sign that newfound business demand for technology is continuing.

On the downside, however, shares of Monsanto took it in the chin last week after the maker of seeds and chemicals sharply lowered its earnings outlook and cash flow projections for fiscal 2010. The lowered guidance comes as Monsanto repositions its Roundup herbicide business due to intense competition from China. The company is streamlining its product line and seeking to re-price its products closer to generic competition to better compete.

Interested in the other stocks on this list? Visit The Motley Fool's free CAPS community for further research and opinions on these stocks!

Related Foolishness:

Fool contributor Jennifer Schonberger does not own shares of any of the companies mentioned in this article. You can follow her on Twitter. Monsanto and Sprint Nextel are Motley Fool Inside Value selections. Titanium Metals is a Motley Fool Stock Advisor recommendation. Motley Fool Options has recommended a synthetic long position on Monsanto. The Fool has a disclosure policy.