He also said Facebook is , will dive into search at some point, and no, they are not building a phone. Seriously, he can't emphasize it enough -- there will be no Facebook phone.

"The performance of the stock has obviously been disappointing," he said during an on-stage interview at the TechCrunch Disrupt conference in San Francisco late Tuesday afternoon. "How well we do with mobile is a big part of it... A lot of stuff has changed. Six months ago we hadn't launched our new apps, Apple hadn't announced their new iOS integration. People shouldn't underestimate how fundamentally good mobile is for us."

Facebook's initial public offering this past May largely to investors and other players in the social networking world.

In the months running up to the company's IPO, there had been great expectations, with analysts and investors predicting that Facebook's stock would take off, soaring from its opening price of $38 a share to $50, $60 or even as high as $90.

However, that hasn't happened. Instead, the company's IPO has been hammered, sinking instead of growing. On Tuesday, the company's stock closed the day at $19.43.