Sergey Brin (net worth: $37.8 billion)

Russian-born American Sergey Brin is the president of Alphabet, the holding company that owns Google, the world’s largest search-engine operator, which he co-founded in 1998. The Mountain View, California-based company handles more than 3.5 billion searches a day and had revenue of $75 billion in 2015. Other units include research division Google X.