Tim Cook

Last year Apple became the first U.S. company to be worth $1 trillion, thanks to the dominance of the iPhone; it lost that status because iPhone sales growth is slowing, and Apple needs a new act. Cook knows it, too, and Apple’s “pivot” to services and subscription revenue, unveiled in March, is his bid to reignite growth. Succeed or fail, the reimagining will determine Cook’s legacy—and Apple’s future.