20. Ken Griffin, 44, is worth an estimated $4.4 billion. He made his money through his Citade return in 2012.
19. Jerry Yang, 44, left, is worth an estimated $1.7 billion. Yang made his money by founding January 2012.
18. David Einhorn, 44, is worth an estimated $1.4 billion. He made his money by founding Greenlight Capital.
17. Milane Frantz, 44, is worth $5.5 billion and is the daughter of the late Dan Duncan, who Houston. Duncan died in 2010.
16. Eric Lefkofsky, 44, is worth an estimated $1.75 billion. He made his money as an investor and founder of Groupon.
15. Elon Musk, 42, is worth an estimated $8 billion. Musk has numerous projects, but he is most notably associated with Tesla, a luxury electric carmaker.
14. Daniel Ziff, 41, is worth an estimated $4.6 billion. He is the son of publishing czar Williams Ziff Jr., who died in 2006.
13. Michael Rubin, 41, is worth an estimated $2.3 billion. He made his money from the e-commerce company GSI Commerce. The company was purchased by eBay for $2.4 billion in 2011.
12. Kevin Plank, 41, is worth an estimated $1.7 billion. He made his money by starting Under Armour Inc.
11. Larry Page, 40, is worth an estimated $24.9 billion. Page co-founded Google with Sergey Brin.
10. Sergey Brin, 40, is worth an estimated $24.9 billion. He made his money by co-founding Google with Larry Page.
09. John Arnold, 39, is worth an estimated $2.8 billion. He made his fortunes working in the hedge fund business. He is one of two young billionaires from Houston.
08. Chase Coleman, 38, is worth an estimated $1.4 billion. He made his money through his Tiger Global hedge fund.
07. Nick Woodman, 38, is worth an estimated $1.3 billion. He made his money by founding GoPro.
06. Jack Dorsey, 36, is worth an estimated $1.3 billion. He made most of his wealth by investing in the mobile payment company Square. Oh, he also started Twitter.
05. Robert Pera, 35, is worth an estimated $1.95 billion. He made his money by starting Ubiquiti Networks. He purchased the Memphis Grizzlies in 2012.
04. Sean Parker, 33, is worth $2 billion. Parker started Napster, and he also served as Facebook?s first president. He did all of that before turning 25.
03. Scott Duncan, 30, is worth an estimated $5.5 billion. He inherited his fortune from Dan Duncan, founder of Enterprise Products billionaire and one of two young billionaires from Houston.
02. Mark Zuckerberg, 29, is worth $19 billion. Zuckerberg made his cash after starting up Facebook.
01. Dustin Moskovitz, 29, is worth $5.2 billion, and he?s the world?s youngest billionaire. Moskovitz was Mark Zuckerberg?s former roommate, and he helped launch Facebook with Zuckerberg.
