Yuri Milner

Named for the cosmonaut and first person to reach outer space, the Russian physicist-turned-investor made his billions placing early bets on technology names such as Facebook and Airbnb. Now he’s backing bigger scientific gambles, such as a project to find signs of intelligent life elsewhere in the universe. He has also persuaded his pals, Facebook’s Mark Zuckerberg and Alibaba’s Jack Ma among them, to fund major awards for physicists, biologists, and mathematicians; the Breakthrough Prizes have given away nearly $200 million to date.