has fallen well below its 38 US dollars (£24) initial public offering (IPO) price in the social network's second day of trading as a public company.
Investors and technology industry watchers are closely tracking the California-based company's shares. The world's largest online social network was one of the most anticipated initial public offerings ever and now serves as a bellwether for other social media companies.
Facebook made its market debut on Friday, with trading on the Nasdaq delayed for a half hour. The stock closed just a few cents above where it priced on Thursday night, when many investors had hoped for a big first-day pop.
The shares opened on Friday at 42.05 US dollars (26.58) and fluctuated throughout the day before closing at 38.23 US dollars (£24.17).
Wedbush analyst Michael Pachter, who came out with an "Outperform" rating on Facebook before its IPO, said he thinks the underwriters overestimated demand for the company's stock.
Last week, the underwriters, led by Morgan Stanley, increased the offering price range.
On Wednesday, Facebook's early investors and other stockholders increased the number of shares they were selling in the IPO. Both had seemingly been signals that there was strong demand for shares.
"The late addition of 84 million shares to the offering overwhelmed demand, limiting the first day price," Mr Pachter said in a note to investors.
On Monday, Facebook stock fell 4.22 US dollars, or 11%, to 34.01 US dollars (£21.51) in morning trading.
Shares had dropped as low as 33 US dollars.