Company: Spotify

Net worth: $310 Million (est.) 

Ek has an entrepreneurial resume that spans back to 1997, when he was 14 years old. He's served as CEO for BitTorrent giant, µTorrent, then linked up with co-founder of Trade Doubler Martin Lorentzon to build the popular music streaming service, Spotify. Scoring $15 million in funding from Napster co-founder, Sean Parker, and landing a partnership with Facebook, the company’s rumored to be worth $4 billion.