The S-1 doesn’t appear to spell out how many shares Mark Zuckerberg has sold of his company that’s causing a full on freak-out on the tech blogs today. Seriously, Dan Primack might lose his mind over that stat alone.

It does show that Zuckerberg owns 28% of the company. Back in 2006, when Facebook turned down the Yahoo offer, Zuckerberg owned about one-third of the stock. The company has raised nearly $2 billion in capital since then. I don’t know enough about how dilution works and the valuation of each round to calculate what that means, but it means one thing for sure: Facebook hasn’t been Zuckerberg’s personal piggy bank up until now.

He’s the anti-Andrew Mason.

It lends credence to a rumor I heard from a Facebook insider last week, that Zuckerberg actually borrowed money from his co-founder Dustin “world’s youngest billionaire” Moskovitz* to make the down payment on his recent house. In fact from what I understand from sources, the largest disbursement of his stock to date has been his $100 million donation to the New Jersey School System.

That’s awesome and deliciously ironic. The entire reason Facebook got away with waiting so long to file was its innovative use of secondary markets, which I wrote about at length here. It seems Zuckerberg himself was one of the only ones not to take full advantage of it.

What’s more valuable to Zuckerberg than billions of dollars in liquid cash? What’s always been important to him where Facebook is concerned: Control.

From the S-1:

“Our CEO has control over key decision making as a result of his control of a majority of our voting stock. As a result of voting agreements with certain stockholders, together with the shares he holds, Mark Zuckerberg, our founder, Chairman and CEO, will be able to exercise voting rights with respect to an aggregate of shares of common stock, representing a majority of the voting power of our outstanding capital stock following our initial public offering. As a result, Mr. Zuckerberg has the ability to control the outcome of matters submitted to our stockholders for approval, including the election of directors and any merger, consolidation, or sale of all or substantially all of our assets. In addition, Mr. Zuckerberg has the ability to control the management and affairs of our company as a result of his position as our CEO and his ability to control the election of our directors.”

(*I saw Moskovitz last night at the Crunchies and he insisted I refer to him this way in every post on PandoDaily. In case you’ve never met him, let me emphasize that that is 100% a joke. He may be the world’s most modest billionaire in addition to the youngest.)