[8] Rosenstein founded hedge fund firm JANA Partners, in 2001, with about $35 million.
[5][9] Rosenstein is ranked with activist investors including Carl Icahn, Daniel Loeb and Bill Ackman.
[8] In April 2017, he made public that he and several investors owned 8.8% of Whole Foods, making them the second largest shareholders of the company after The Vanguard Group.
[11] Through JANA Partners, Rosenstein buys large percentages of companies which he identifies as underperforming.
[12][13] Rosenstein serves on the board of trustees of Brown University, the Rock and Roll Hall of Fame and 92nd Street Y.