In his first interview since Facebook’s rocky initial public offering on 18 May, the social networking guru revealed his stock has lost nearly half its value, going down at a rate of about £47 million per day.
The company’s market value has fallen by more than £31.2bn and the price of Facebook shares is down from $38 to less than $20 each.
But Mr Zuckerberg, 28, who founded the company eight years ago in his Harvard University dormitory, said he was relishing the opportunity to prove his critics wrong.
Before a standing-room-only audience at a conference in San Francisco, he said: “I would rather be in a cycle where people underestimate us, because I’d rather be underestimated. I think it gives us the latitude to go out and make some big bets.”
Wearing a grey T-shirt, jeans and trainers, Mr Zuckerberg was clearly aiming many of his remarks at investors, emphasising that Facebook cared about making money as well as his mission to make the world a “more open and connected place”.
He repeated his belief that the company would work out numerous ways to profit from the growing number of its 955 million worldwide users who visit it through mobile applications instead of web browsers on desktop computers.
Mr Zuckerberg said the performance of Facebook’s stock “has obviously been disappointing”, but added it was a great time to “double down” on the company’s future.
“I think it is really easy for folks to underestimate how really fundamentally ‘good mobile’ is for us,” he said.
He shouldered some of the blame for the misconceptions about Facebook’s mobile prospects, saying he made a mistake by initially relying on the web language HTML5 so the company’s applications could run on a multitude of different mobile operating systems without making a lot of changes.
That resulted in below-par experiences for many users, Mr Zuckerberg said, prompting Facebook to use more customisation tools to account for the differences in the software that runs different devices such as the iPhone and Android phones.
Smartphones have created problems for Facebook because the smaller screens have less space to show advertising next to the main content.
One way Facebook will address that challenge is by inserting more ads into the mobile news feeds that highlight status updates and photos shared by users’ friends and families, according to Mr Zuckerberg.
He once again denied that Facebook is developing its own smartphone like Apple and Google: “It is so clearly the wrong strategy for us,” he said.