Jana Partners sold 474,000 shares of Facebook, according to a required quarterly filing with the U.S. Securities and Exchange Commission on Tuesday. The data reflect changes made at some point in the first quarter.
It is not known whether Jana sold out before Facebook dropped more than 20 percent after revealing a consumer data scandal affected 87 million accounts. As of the end of December, Jana's Facebook stake was worth $84 million.
The hedge fund did not immediately respond to a CNBC request for comment.
In January, Jana Partners and the California State Teachers' Retirement System (CalSTRS) sent an open letter to Apple asking the tech giant to create software that would allow parents more control of what their children can access through an iPhone.
"It is also no secret that social media sites and applications for which the iPhone and iPad are a primary gateway are usually designed to be as addictive and time-consuming as possible, as many of their original creators have publicly acknowledged," the letter said.
Apple said in a statement at the time that since 2008, iPhone software has let parents decide which apps, movies, games and other content children can access.
Jana bought 271,000 shares of Apple in the first quarter, the filing showed. The stake was worth $45.5 million as of the end of March.
CalSTRS held 9.1 million shares of Apple, or 0.18 percent of shares outstanding, as of the end of the fourth quarter, according to FactSet. First-quarter data was not available as of Tuesday morning.