"Nothing in that [falling prices] has made me think that the fundamental strategy is wrong," Zuckerberg said at the company's first annual shareholders meeting as a public company.
The Wall Street Journal reported Wednesday Zuckerberg was "grilled" by shareholders for a half hour, some of them angry their investment in the company had not panned out.
One shareholder who asked a question called the stock price "a disaster."
At close to $24 per share, Facebook stock is now valued at 40 percent of its launch price.
Zuckerberg attempted to deflect the criticism by calling it part of a normal business cycle.
"We're disappointed with the performance of the stock over the last year. We expect there's going to be fluctuations," he said.
How long would it take for shareholders to see a return on their investment -- "two years?" one shareholder asked.
"I wish I had a crystal ball," Facebook Chief Financial Officer David Ebersman answered.