Facebook stock performance has been disappointing: Mark Zuckerberg

Facebook CEO Mark Zuckerberg hasn't enjoyed seeing his company's stock get pummeled on Wall Street this summer, but he is relishing the opportunity to prove his critics wrong.

The social networking leader's stock has lost nearly half its value since the initial public offering (IPO) in May. More than $50 billion has been lopped off Facebook's market value as the company's shares have fallen from $38 to Tuesday's closing price of $19.43.

"I would rather be in a cycle where people underestimate us because I'd rather be underestimated," Zuckerberg said on Tuesday. "I think it gives us the latitude to go out and make some big bets."

Zuckerberg, 28, made his remarks before a standing-room-only audience at a tech conference in San Francisco in his first interview since Facebook Inc's rocky IPO.

No one has lost as much as Zuckerberg, who has seen the value of his Facebook holdings fall about more than $9 billion . That while hearing more skeptics second-guess his ability to lead the company that he founded eight years ago in his Harvard University dorm room.

Since speaking during Facebook's first earnings conference call as a public company nearly seven weeks ago, Zuckerberg has remained largely out of the spotlight.

Wearing a gray T-shirt, jeans and sneakers, Zuckerberg looked at ease through his half-hour appearance. He smiled frequently and even chuckled a few times before a San Francisco audience composed largely of fellow geeks who, like him, tend to enjoy talking about computer coding and building cool products instead of discussing revenue growth and business strategies.

Yet Zuckerberg clearly was aiming many of his remarks at investors.

He emphasised that Facebook cared about making money as well as pursuing his mission to make the world a "more open and connected place." He also repeated his belief that the company would figure out numerous ways to profit from the growing number of its 955 million worldwide users who visit is online hangout through mobile applications instead of Web browsers on desktop computers.

Zuckerberg said the performance of Facebook's stock "has obviously been disappointing," and will probably cause some demoralized employees to defect. But he said he hopes most workers will stay and "double down" on Facebook's future.

"I think it is really easy to for folks to underestimate how really fundamentally good mobile is for us," Zuckerberg told his interviewer, former blogger turned venture capitalist Michal Arrington, at the TechCrunch Disrupt conference.

Zuckerberg shouldered some of the blame for the misperceptions about Facebook's mobile prospects, saying he made a mistake by initially relying on a computer coding called HTML 5 so the company's applications could run on a multitude of different mobile operating systems without making a lot of changes.

That resulted in sub-par experiences for many users, Zuckerberg acknowledged, prompting Facebook to use more customistion tools to account for the differences in the software that run different devices such as the iPhone and Android phones.

Some investors evidently liked what Zuckerberg had to say. Facebook shares gained 66 cents, or 3.4 per cent in Tuesday's extended trading after he took the stage.

Zuckerberg has signaled his faith in Facebook's stock by pledging not to sell any of his more than 503 million shares for at least another year, even as some of the company's early investors and employees reduce their holdings.

Tuesday gave him an opportunity to deliver a reminder that Facebook has overcome past adversity when changes to its website's design and privacy policies provoked strident objections from users who threatened to abandon the social network. Facebook overcame those protests to keep on growing.

"Facebook has not been an uncontroversial company," Zuckerberg said. "It's not like this is the first up and down we have ever had."