Chairman and CEO, Mondelez International
The past year can’t have been much fun for Rosenfeld, thanks to pressure from major investors Nelson Peltz and William Ackman that led to intense cost cutting. But it paid off: Mondelez stock rose 23 percent in 2015, handily beating both its industry peers and the S&P 500. Her next tasks are to goose growth and profits at the $28 billion snacks maker—and, of course, to manage Peltz and Ackman’s continued demands. But if anyone can slog it out, Rosenfeld can.