The S&P 500 tumbled 2.5% last week, to 1,186.69, after a volatile week that brought news of a criminal investigation into Goldman Sachs doings, evidence that the sovereign debt crisis in Greece is spreading to the rest of Europe, and encouraging economic data. The index ended the month of April up 1.5%.

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

Akamai Technologies (Nasdaq: AKAM)

13.5%

Tellabs

8.5%

First Solar

7.6%

Whirlpool

6.5%

NRG Energy

6.1%

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

Losers on the week:

Company

Percentage Loss on the Week

Harman International (NYSE: HAR)

(24.0%)

Eastman Kodak

(23.4%)

Office Depot

(18.8%)

MEMC Electronic Materials

(18.0%)

Massey Energy

(17.6%)

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

A closer look
Shares of Akamai Technologies rose after the company reported first-quarter results that trumped analysts' expectations. Profits rose 10% in the quarter, while revenue increased 14%, with higher-margin services comprising more than half the company's revenue. Akamai, whose clients include Apple and News Corp., offers products and services that improve the delivery of content over the Internet.

On the flip side, shares of Harman International got pummeled after the maker of audio products and electronic systems said its revenue growth would decelerate within the next few years. The company also said it continues to see weaker margins compared with prerecession levels. That bad news outweighed Harman's fiscal-third-quarter results, in which it reported a profit compared with a loss a year ago and a revenue rise of 42%. Separately, Harman said it purchased Brazilian speaker company Eletronica Selenium.

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. Akamai Technologies and First Solar are Motley Fool Rule Breakers selections. Apple is a Motley Fool Stock Advisor recommendation. The Motley Fool has a disclosure policy.