CEO and President, Fidelity Investments, 53
In October 2014, in a long-anticipated move, Abby Johnson succeeded her father, Ned, as CEO of the nation’s second-largest fund manager. That puts her in charge of assets totaling $5.3 trillion. She’s already cut costs and made major staffing changes—demonstrating that she’s not afraid to shake things up. Johnson will need to nurture that bold streak to keep the company moving forward: The trend away from funds run by stock pickers—Fidelity’s bread and butter—cost it $16 billion worth of business in 2014.