SAN JOSE, CA - FILE: Packages of DVDs await shipment at the headquarters January 29, 2002 in San Jose, California. (Justin Sullivan/GETTY IMAGES)

Netflix shares jumped sharply in afternoon trading Wednesday on word that billionaire investor Carl Icahn’s group, Icahn Capital, has bought a 9.98 percent stake in the company.

It was the first day of trading on the New York Stock Exchange since the markets were closed Monday and Tuesday after New York City took a direct hit from mega-storm Sandy.

The Netflix news, detailed in a filing with the Securities and Exchange Commission, sent shares up over 15 percent. The stock closed up at $79 per share.

A report from Barron’s said that the spike prompted Nasdaq to briefly halt trading.

In the filing, the Icahn group said it believes that Netflix stock is undervalued and that the video rental and online streaming company “may hold significant strategic value” for companies looking to engage more with the Web and mobile platforms.

Icahn’s group and its entities acquired 5.54 million shares of stock in the company, totaling $168.9 million.

Last week, Netflix cut its estimates for how many video-streaming subscribers it would add this year, sending its stock down in after-hours trading. The Icahn investment gives it a much-needed boost.

Other tech stocks didn’t fare as well on Wednesday. Apple and Facebook both fell. Apple’s stock was down about $8 a share, or 2 percent, after an executive shakeup at the company that will see mobile operating system head Scott Forstall leave Apple next year.

Facebook’s shares were down nearly 4 percent, or 82 cents per share, following the expiration of a stock “lock-up” that made more of the company’s share available for trading on the open market. The lock-up expired on Monday.

At market close, the Dow was slightly down, 0.1 percent; the Nasdaq down 0.36 percent; and the Standard & Poors was barely up, by 0.02 percent.

(The Washington Post Co. chairman and chief executive Don Graham is a member of Facebook’s board of directors.)

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