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:

Company

Percentage Gain
on the Week

Newmont Mining (NYSE:NEM)

12%

Textron

9%

Motorola (NYSE:MOT)

7%

Costco Wholesale (NASDAQ:COST)

7%

BJ Services (NYSE:BJS)

7%

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

Losers on the week:

Company

Percentage Loss
on the Week

AIG (NYSE:AIG)

(20%)

McGraw-Hill

(13%)

SunTrust Banks

(12%)

Moody’s (NYSE:MCO)

(11%)

Gannett (NYSE:GCI)

(11%)

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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