Family Dollar's shares gained more than 9 percent in after-hours trading when activist investor Carl Icahn disclosed a 9.4 percent position in the company. "Hope to continue our streak of value enhancement," Icahn said, in a tweet.
In the official 13D filing with the SEC, Icahn said he acquired the shares because he believes they are undervalued, and that he wants to talk with senior management and board of directors about "the pursuit of operating initiatives or the exploration of strategic alternatives."
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If appropriate, Icahn also said in the document that he would seek board representation.
Icahn is not the first big-name investor to take a stake in Family Dollar. Nelson Peltz's fund owns 7 percent of the company, or 8.5 million shares, while John Paulson has a 5.7 percent stake.
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—By CNBC.com