Facebook shares on Monday fell below $19 for the first time -- less than half the $38-a-share price of its initial public offering.
After closing at $19.07 Friday, Facebook shares slid to a new low of $18.75 in midday trading. The stock recouped the loss and was later trading at well over $19 a share.
Late last week, Facebook shares took a hit after the expiration of a provision that had barred certain investors and insiders, including employees, from trading some of their shares.
A Los Angeles Times story last week also noted that investors have begun wondering aloud whether Facebook co-founder Mark Zuckerberg is cut out to continue being the company's chief executive.