Facebook's stock price fell almost 10% on Tuesday leading analysts to declare its initial public offering (IPO) last Friday as one of the worst in financial history.
The social network's Nasdaq trading price fell as low as $28.65, down from $38 or more than 20% since its launch.
Facebook raised $16bn in its IPO, but has subsequently produced the worst five-day return among the 10 largest US IPOs in the last decade.
The stock began the day at $31.69 but plummeted in afternoon trading.
Bloomberg analyst Sheila Dharmarajan said the IPO was the biggest flop in 10 years, and had produced the worst return among virtually any recent deal of its size.
However some analysts remained optimistic, with one pointing out that Amazon's own stock price fell well below its own IPO value for months before recovering.
Facebook's CEO Mark Zuckerberg remains on his honeymoon with new wife Priscilla Chan in Italy.
The company is already facing lawsuits after investors claimed they were misled about the true value of its stock before the IPO.
Meanwhile the Facebook debacle is leading other social networks around the world to reconsider their own IPOs, with the leading social service in Russia, Vkontakte, which has 119m users, pulling its floatation for the foreseeable future.
Facebook however was said to be in discussions about purchasing the mobile operating system Opera for as much as $1bn, matching the price it paid for photography app, Instagram.
It has also been rumoured recently that Facebook is planning on developing its own phone although details remain thin on the ground.
See below to find out what CEO Zuckerberg has been up to while his company's stock has plummeted.