11) Ryan Graves (Age: 31; Net worth: $1.4 billion)

Ride-hailing service Uber is valued at $41.2 billion. Ryan was the first employee hired at Uber. He joined Uber in 2010 when its CEO tweeted that he was looking for a product manager.

10) Nathan Blecharczyk (Age: 31; Net worth: $1.9 billion)

In 2008, this young billionaire co-founded Airbnb, a popular website for people to rent out lodging. He is the chief technology officer of the company. Airbnb lists one million homes for rental stays.