Facebook finished second to Google, at least on the annual 40 Under 40 list from Fortune, as Facebook Co-Founder and CEO Mark Zuckerberg came in at No. 2, trailing only Google Co-Founder and CEO Larry Page.

Fortune wrote in its profile of Zuckerberg:

Facebook’s stock may have taken a beating since its $104 billion stock market initial public offering in May, but eight years after Zuckerberg founded the social network in his Harvard dorm room, it continues to dominate: 1 billion active users have uploaded a total of 219 billion photos and given a thumbs-up like 1.13 trillion times since launch. The company also released major updates to its mobile applications, and, reflecting Zuckerberg’s philosophy of full-steam ahead, the Facebook founder hired architect Frank Gehry to expand the company’s already vast Menlo Park, Calif., headquarters.

Mobilize: Zuckerberg is so attached to his smartphone, he used it to write his founder’s letter for Facebook’s S-1 stock registration — all 2,178 words of it.

Joining Page and Zuckerberg on the 40 Under 40 list from the tech sector were:

  • No. 3: Yahoo President and CEO Marissa Mayer.
  • No. 4: Google Co-Founder Sergey Brin and Square Founder and CEO Jack Dorsey, also co-founder and executive chairman of Twitter.
  • No. 15: Google Senior Vice President of YouTube and Video Salar Kamangar.
  • No. 17: Airbnb Co-Founder and CEO Brian Chesky.
  • No. 18: Pinterest Co-Founder and CEO Ben Silbermann and Instagram Co-Founder and CEO Kevin Systrom.
  • No. 19: Wildfire Co-Founder and CEO Victoria Ransom and Buddy Media Co-Founder and former CEO Michael Lazerow.
  • No. 20: Spotify Co-Founder and CEO Daniel Ek and Gree Founder and CEO Yoshikazu Tanaka.
  • No. 21: Kickstarter Co-Founder and CEO Perry Chen, Co-Founder Charles Adler, and Co-Founder Yancey Strickler.
  • No. 23: Hearsay Social Co-Founder and CEO Clara Shih.

Readers: What do you think Zuckerberg has to do to leap into the top spot?