Facebook Inc (NASDAQ:FB) CEO Mark Zuckerberg’s total pay in 2013 fell 67% from $2 million in 2012. According to regulatory documents filed on Monday, Zuckerberg has restricted his annual salary to just $1. However, the 29-year old billionaire reaped a whopping $3.3 billion gain from stock options. The windfall saddled him with a huge tax bill despite just $1 in salary.

Mark Zuckerberg Facebook

Facebook CEO has exhausted all his stock options

It’s the second consecutive year that the Facebook Inc (NASDAQ:FB) founder and CEO has realized hefty gains from stock options. In 2012, Mark Zuckerberg made $2.3 billion by exercising stock options. Documents show that he has exhausted all his stock options. Zuckerberg exercised 60 million options last year at 6 cents a share. Then he offloaded 41.35 million shares at $55.05 each in December to cover his tax bill. Mark Zuckerberg also donated 18 million Facebook shares to a Silicon Valley charity.

Facebook Inc (NASDAQ:FB) shares have surged more than 135% over the past 12 months. Mark Zuckerberg delivered on his promise to generate more revenue from mobile advertising. The world’s largest social networking company generated more than 53% of its advertising revenue by selling ads on smartphones and tablets.

Facebook CEO still owns 426.3 million shares

He has also made some strategic acquisitions such as the $19 billion purchase of WhatsApp, and the $2 billion acquisition of Oculus VR. Both purchases have been criticized by a section of experts. But Mark Zuckerberg has defended these acquisitions. WhatsApp has more than 450 million active users, but it generated only $23 million in revenues last year. And Oculus VR’s virtual reality technology is still largely unproven.

Even after donating and selling so many shares, Mark Zuckerberg still owns 426.3 million shares of the company, which are valued at $25.7 billion. Besides his $1 salary, Facebook Inc (NASDAQ:FB) CEO also received $653,164 in perquisites. A large chunk of that sum went towards Mark Zuckerberg’s bills for personal travel on chartered airplanes.

Facebook Inc stock went up 0.45% to $60.51 in pre-market trading Tuesday.