Forbes 400: America's Top 15 Richest Techies

6. Mark Zuckerberg

Mark Zuckerberg, 29, is co-founder and CEO of Facebook. According to Forbes, Zuckerberg's net worth jumped in the past 12 months landing him on the 20th spot on Forbes' list, up from No. 36 in 2012, thanks in large part to doubling the company's shares in the past year.

Forbes 400 Ranking: 20

Net Worth: $19 billion