Carl Celian Icahn (/ˈaɪkɑːn/; born February 16, 1936) is an American activist shareholder. He is the founder and controlling shareholder of Icahn Enterprises, a public company and diversified conglomerate holding company based in New York City. Icahn takes large stakes in companies that he believes will appreciate via changes to corporate policy and he then pressures management to make changes that he believes will benefit shareholders. He was one of the first activist shareholders and is credited with making that investment strategy mainstream for hedge funds.