Facebook' s 27-year-old founder Mark Zuckerberg could land a a fortune valued at $21 billion to $28 billion as a result of the IPO.
The paperwork that Facebook filed on Wednesday reveals that he owns around 28% of the company, and is its single largest shareholder.
If Facebook finishes with a high-end valuation of $100 billion, his stock would be worth $28 billion, said the Wall Street Journal.
Also revealed: Zuckerberg was paid $1.49 million last year in salary, bonus and other compensation for his role as chief executive.
Facebook's filing said he would sell shares in the IPO, but didn't say how many. He will use the proceeds to pay taxes.
At $28 billion Zuckerberg would have been No. 9 in Forbes magazine's rich list last year. Ahead of him: Bill Gates of Microsoft and Larry Ellison of Oracle.
But, said the WSJ, Zuckerberg has already shown he doesn't intend to act like a typical billionaire.
In a 2,200-word letter filed with Facebook's IPO paperwork, Zuckerberg "wasn't shy about his social ambitions, even as he played down the importance of running a business." He wrote "Facebook was not originally created to be a company. It was built to accomplish a social mission." .
Society, he wrote, is at a "tipping point" because of the Internet. Facebook gives "people the power to share and help them once again transform many of our core institutions and industries," he added.
That includes changing government, he wrote. "Over time, we expect governments will become more responsive to issues and concerns raised directly by all their people rather than through intermediaries controlled by a select few," he said.
Mark grew up in Dobbs Ferry, New York, the son of a dentist and psychiatrist. he founded Facebook in his Harvard College dorm room, and in the years since " has grown from a college sophomore into a leading voice for a new generation of technology entrepreneurs," said the WSJ.
In the early years after moving to California, he wore Adidas flip-flops to business meetings. He handed out business cards reading, "I'm CEO, B—."
Today, he even wears a sports jacket for special meetings, like with President Barack Obama and Oprah Winfrey.
Not for him the giant mansions and posh cars of the late 1990s dot-com bubble, said the Journal. He lives in a modest house, and takes his dog for long walks. The dog, Beast, a white Hungarian Puli even has its own Facebook page.
In December 2010, he signed a pledge—along with his former roommate and Facebook co-founder Dustin Moskovitz—to give most of his wealth to charity and has already pledged $100 million to public schools in Newark, New Jersey.