Bob Iger stepped down as CEO of Disney on Tuesday and assumed the role of executive chairman. He was replaced by Bob Chapek, the former head of Disney parks. Iger, 69, joined Disney when it bought ABC in 1996. In 2000, Iger was named president and COO of Disney. Five years later, he became the sixth CEO in the company’s history. Shares of Disney fell about 2.5% hours after the news was announced.