The S&P 500 skidded 2.3% last week to 1,064.88, as a disappointing jobs report for May and concerns over Hungary's fiscal situation pushed the market lower.

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

Winners:

Company

Percentage Gain

Southwestern Energy (NYSE: SWN)

10.9%

Chesapeake Energy (NYSE: CHK)

7.8%

Range Resources

7.5%

WellPoint (NYSE: WLP)

5.5%

Akamai Technologies

5.5%

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

Losers:

Company

Percentage Loss

Tellabs (Nasdaq: TLAB)

(22.4%)

FMC Technologies

(15.2%)

Tenet Healthcare (NYSE: THC)

(14%)

Anadarko Petroleum (NYSE: APC)

(13.8%)

Cliffs Natural Resources (NYSE: CLF)

(11.9%)

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

A closer look
Most individual stocks were driven by macroeconomic factors last week. Natural gas producers Southwestern Energy and Chesapeake Energy got a boost after natural gas prices soared after a weekly inventory report that showed supplies increased by less than anticipated, expectations for a hot summer, and uncertainty surrounding the oil spill in the Gulf of Mexico.

One energy company that didn't feel the love was Anadarko Petroleum. Moody's downgraded the oil and gas exploration and production company's debt to negative from stable on Anadarko's financial liability for cleanup of the oil spill in the Gulf. Moody's estimates that Anadarko has 25% share of the cleanup efforts because it owns 25% of the deepwater well that exploded. Cleanup costs have been estimated at around a billion dollars so far.

Also on the downside, shares of Tenet Healthcare were hit hard after Goldman Sachs downgraded the hospital operator to neutral from buy, citing a possible impact on earnings should the company's offer to acquire Australian company Healthscope materialize. Also, a major shareholder of Tenet has expressed opposition to the potential acquisition, saying that the progress the company has made domestically is encouraging, and diversifying outside of the U.S. market could prove a risky move in light of changes from health-care reform.

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