38. Elon Musk

Title: CEO, Tesla and SpaceX

Country: US

Age: 44

The man who believes there's "no such thing as business, only the pursuit of a goal" has invested in, founded, or run 18 companies to date, including two of the most innovative technology firms in America: Tesla Motors and SpaceX. It was a big year for both companies, with retail deliveries of the Tesla Model X crossover vehicle starting in September and the launch (and failure) of a SpaceX rocket bound for the International Space Station in June. Anticipation is already high for the mass-market Model 3 sedan, which Tesla plans to unveil next March, and another SpaceX supply launch set for December.

Musk, who first hit it big cofounding PayPal in the late 1990s, has a growing fortune of more than $11 billion that enables him to experiment with technology of the future. In January, he announced via Twitter that he would build a five-mile Hyperloop test track to invite students and companies to test out their ideas for the high-speed transportation system. He also donated $10 million to the Future of Life Institution this year to keep artificial intelligence safe and beneficial to humans.