Dan Loeb 's hedge fund, Third Point, sent a letter to its investors on Monday. Third Point identifies itself as a macro- and event-based fund, but is mostly known for its shareholder activism. It has had some notable wins in recent years, including doubling its investment in Yahoo! Inc. (NASDAQ:YHOO). In its recent letter, Third Point writes that it has initiated a stake in CF Industries Holdings, Inc. (NYSE:CF), sold most of its Yahoo! Inc. (NASDAQ:YHOO) shares, and continues to pressure Sony Corporation (ADR) (NYSE: SNE )'s management to spin off its entertainment division. Third Point's case for CF CF Industries Holdings, Inc. (NYSE:CF) is a major North American producer of fertilizer. Third Point believes that the company is misunderstood and undervalued, and that management should be able to increase the firm's dividend going forward.