LinkedIn, AOL surge, leading techs higher

SAN FRANCISCO (MarketWatch) � Big jumps at LinkedIn Corp. and AOL Inc. led the tech sector to strong gains Friday, as investors at the two growing Internet brands cheered the companies� recent quarterly results.

Adam Barker/LinkedIn LinkedIn surges to a new high on Friday following fourth-quarter results.

The Nasdaq Composite COMP � rose 29 points, or nearly 1%, to 3,194, while the Philadelphia Semiconductor Index SOX � rose 1% and the Morgan Stanley High-Tech Index MSH �edged up about 0.7%.

LinkedIn LNKD shares jumped more than 18% to $147.32 � putting the stock to a new high and bringing gains over the past 12 months to more than 90%. The professional social network blew past Wall Street�s targets for the fourth quarter and issued a forecast that was also above analysts� estimates. See: LinkedIn crushes targets; shares jump

Gene Munster of Piper Jaffray lifted his price target on the stock to $176 from $150, writing in a note that the company �is still in the relatively early stages of fully monetizing its professional network asset and that the company has the path to continue to grow in the mid-double digit range for at least the next three years.�

/quotes/zigman/5131883/quotes/nls/lnkd LNKD 151.79, +27.70, +22.32%

AOL AOL � shares rose nearly 7% to $33.47 after the company reported a 57% jump in net income for the fourth quarter, with revenues above analysts� forecasts. See: AOL profit up 57% on advertising growth

Apple AAPL �shares picked up 1.7% in gains to come to $476.15. The stock got a late-day boost Thursday after the company issued a statement saying that it would evaluate a proposal from hedge-fund giant David Einhorn, who�s pushing the company to return more cash to shareholders through use of preferred stock. See: Apple sued by Einhorn over stock proposal

The company also maintained � however � that it is sticking by its proposed amendment on its proxy statement to eliminate the ability to issue such stock without shareholder approval.

Videogame publisher Activision Blizzard ATVI � jumped more than 11% following its own better-than-expected results. Analysts from Macquarie Capital and Sterne Agee upgraded the stock to the equivalent of buy ratings. See: Activision hits big ahead of challenging year

Click to Play YouTube sees pirated content return

YouTube is facing the return of a pirated-content problem. Hundreds of full-length feature films, including blockbusters from Disney and Sony have been illegally uploaded to the world's most popular video site.

�With the initial 2013 guidance now official, continued strength in core franchises, a solid pipeline of new IP, and the increased likelihood of a more shareholder-friendly capital structure, the next catalysts for Activision are likely positive, in our view,� wrote Ben Schachter of Macquarie in a note to clients.

One notable decliner was Riverbed Technology RVBD �, down nearly 19% after reporting a sharp drop in profit and disappointing outlook. Daniel Ives of FBR Capital downgraded the stock to a market perform rating following the results.

�While we had some concerns initially around the OPNET acquisition (October 2012), it appears Riverbed has an even tougher road ahead than we previously thought due to integration issues related to the acquisition, coupled with headwinds on its core WAN optimization business,� he wrote.

Coinstar CSTR �, the owner of the Redbox DVD kiosk business, fell 8% after the company reported a decline in earnings and an outlook that was below expectations.