Nasdaq alerted traders at 14.16 EST that the circuit breaker had been triggered, according to the Wall Street Journal. A similar sharp drop saw the same thing happen on the stock's debut on 18 May.

Circuit breaker - introduced by the SEC following the 2010 flash crash - pause trading in a stock if its price falls more than 10% from the previous day's closing.

At the close of trading, Facebook's shares were down 9.62%, or $3.07, at $28.84. The stock is down about 24% on its IPO price of $38.