The S&P 500 finished last week lower, slipping 1.2% to 1,016.4; while the index climbed a healthy 3.4% for the month of August. However, the index kicked off September with a rocky start, pulling back for the first couple of days of the month.

Pops and drops
Here are the five biggest S&P 500 pops 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

Newmont Mining (NYSE:NEM)




Motorola (NYSE:MOT)


Costco Wholesale (NASDAQ:COST)


BJ Services (NYSE:BJS)


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

Losers on the week:


Percentage Loss
on the Week





SunTrust Banks


Moody’s (NYSE:MCO)


Gannett (NYSE:GCI)


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

A look at some of the movers
Shares of Moody's and McGraw-Hill, owner of Standard & Poor's, slumped last week after a judge permitted a case brought against the credit rating agencies to proceed. The judge ruled that freedom of speech protections don't necessarily apply to ratings disseminated to a limited group of investors.

Baker Hughes acquired oilfield services company BJ Services last week in a cash and stock deal valued at $5.5 billion. The oil and gas equipment company's purchase will better enable it to compete with larger players in the oil services area, like Schlumberger and Halliburton.  

After rocketing 430% since July 9, and topping the S&P 500’s weekly gainers list last week, AIG is finally falling back to earth.

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Fool contributor Jennifer Schonberger does not own shares of any of the companies mentioned in this article. Costco Wholesale and Moody's are Motley Fool Stock Advisor picks and Motley Fool Inside Value recommendations. The Fool owns shares of Costco Wholesale. The Motley Fool has a disclosure policy.