The sell off continued last week with the S&P 500 falling 0.7% to 1,071.69. The benchmark index is down 3.9% year to date.

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:

Company

Percentage Gain on the Week

McAfee (NYSE: MFE)

57.1%

salesforce.com (NYSE: CRM)

16%

Intuit

15.7%

Symantec (Nasdaq: SYMC)

11.8%

eBay (Nasdaq: EBAY)

8.7%

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

Losers on the week:

Company

Percentage Loss on the Week

DeVry (NYSE: DV)

(11.1%)

SUPERVALU

(8.3%)

Sears Holdings (Nasdaq: SHLD)

(7.5%)

EQT

(7.2%)

Intuitive Surgical (Nasdaq: ISRG)

(7%)

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

A closer look
It's old news that shares of McAfee soared last week after the security software provider agreed to be acquired by chip giant Intel for $7.68 billion -- a 60% premium over McAfee's closing share price prior to the announcement of the deal. Intel sees the move as a way to add security to its computer chips.

In other high-flying stock news, shares of salesforce.com bolted last week on the back of a better-than-expected second-quarter earnings report and a raised full-year revenue outlook. Revenue rose 25% year-over-year, as the cloud computing services provider saw customers surge 30% from the second quarter last year. The quarter shows a push toward cloud computing, as the company says customers are trending toward services like Salesforce's versus investing in hardware. Despite a great growth story and strong financials that are likely to continue, Foolish colleague, Rich Smith cautions valuation may be high. Shares trade at almost 50 times annual cash generation.

On the downside, shares of Sears sauntered lower after the department store delivered a disappointing second quarter. The company clocked a net loss for the quarter that widened from a year ago, as sales waned. Same store sales -- a common benchmark for retailers -- fell 2.2% at American stores. Analysts project increasing costs for clothing will weigh on margins next year, while lapsing government stimulus programs will hinder same-store sales.

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