NEW YORK ( TheStreet) -- Storage specialist NetApp ( NTAP) is proving popular with star hedge fund managers, according to the latest 13F filings with the Securities and Exchange Commission. Citadel Advisors added 5,771,479 NetApp shares to take its stake to 6,535,127, while D.E. Shaw added 994,888 shares, increasing its position to 2,053,775. Steve Cohen's SAC Capital Advisors made a more a modest increase in its position, adding 78,312 shares for a total of 111,765. Shares of NetApp, which competes with EMC ( EMC) and HP ( HPQ), have risen almost 19% over the past three months. The Sunnyvale, Calif.-based firm beat analysts' estimates in its third-quarter results earlier this week, and also delivered robust guidance. Renaissance Technologies, however, cut its position in NetApp by 1,094,100 shares, reducing the stake to 1,528,532. D.E. Shaw had added 630,907 EMC ( EMC) shares by the end of 2012, according to the filing, taking its position to 1,818,535. Citadel Advisors, however, significantly reduced its position in the storage giant to 194,175 shares, from 5,203,504. SAC Capital Advisors also cut its EMC holding to 113,126 shares from 3,481,140. EMC recently edged past Wall Street's estimates in its fourth-quarter results, although tepid guidance weighed heavily on the company's shares. Shares of the Hopkinton, Mass.-based firm are up 2% over three months. -- Written by James Rogers in New York Follow @jamesjrogers >To submit a news tip, send an email to: firstname.lastname@example.org.