Facebook shares dropped sharply in their second day of trading on Wall Street.
Facebook shares lost $4.61, or 12%, to $33.71 after the opening bell.
Major U.S. stock indexes were otherwise up slightly in early trading.
Facebook shares were down as much as 5% before trading opened on Wall Street.
The social networking juggernaut made its stock market debut on Friday.
Shares initially jumped to about $42 a share but wound up settling around their initial $38 price, disappointing investors who were hoping for a first-day pop.
Facebook's debut was also marred by glitches at the Nasdaq stock exchange, frustrating investors and traders.