Microsoft CEO Steve Ballmer needs to be kicked out, a well-known hedge fund investor said Wednesday.

David Einhorn, manager of Greenlight Capital, said Ballmer is stuck in the past and needs to give someone else a chance. “[Ballmer’s] continued presence is the biggest overhang on Microsoft’s stock,” Einhorn said at the Ira Sohn Investment Research Conference in New York.

Chief among Einhorn’s concerns are that Microsoft is missing opportunities to better compete with Apple products like the iPad. He also said he is unhappy with some of Microsoft’s acquisitions over the years.

Greenlight Capital currently holds 9 million shares of Microsoft stock, which amounts to 0.11 percent of company shares. Comparably, Ballmer owns 333 million shares or 3.95 percent. Former CEO Bill Gates owns more than 560 million shares or 6.65 percent.

It’s arguable whether replacing Ballmer would do much for Microsoft’s stock price in the long term, but Microsoft’s stock price was trading up today by 2 percent after Einhorn’s words made headlines.

Microsoft is a strange case when it comes to its stagnant stock price. The company continues to make incredible profits on its Windows and Office software, but its stock price has been sitting between $25 and $30 for most of the 2000s.

Would you like to see Ballmer step down? Do you think Microsoft is heading in the wrong direction?

Update: In the wake of Einhorn’s comments, Microsoft’s board of directors said it stands behind Ballmer, according to Reuters. The report says that the nine-person board, which includes Bill Gates, firmly supports Ballmer.