Facebook's beleaguered stock got an afternoon boost after hitting its lowest level ever earlier in the day.

Facebook hit a new low of $US18.75 before bouncing back to $US20.01 by the time the stock market closed on Monday. That's up 96 cents, or five per cent, for the day.

The social networking icon's much-anticipated IPO turned sour amid technical problems on the Nasdaq stock market and high expectations.

The stock has not surpassed its $US38 IPO price since its first trading day.

Investors are worried about Facebook's ability to grow revenue quickly, especially through mobile advertising as users flock to smartphones and tablet computers.

There are also looming expirations of the IPO lock-up periods. Lockups preventing many Facebook employees from selling stock expire in coming weeks, potentially flooding the market with more shares.