Shares of Facebook (Nasdaq: FB), the No. 1 social network, plunged as much as 13 percent when markets opened Monday, lowering the company's value by about $8 billion. By the close, they'd lost 11 percent, slicing as much as $32 billion from its overall market capitalization.

In early trades, Facebook shares fell $5.18 to $33.05  or 13.5  percent. It was only the second day for the Menlo Park, Calif.-based company's shares to trade. At the close, shares were down $4.20, or 11 percent, at $34.03.

On Thursday, Facebook raised $16 billion in the biggest-ever initial public offering by an Internet company. It was also the second-largest in U.S. history. On Monday, Nasdaq OMX Group (Nasdaq; NDAQ), the all-computerized exchange that conducts all Facebook trading, blamed software for glitches that slowed down first-day trading. Nasdaq said it unable to manage orders to buy Facebook shares at $42 against many cancellations of orders at $38.

Later, principal underwriter Morgan Stanley (NYSE: MS) reported Facebook orders exceeding $30 million left over from Friday that still hadn't been executed.

Nasdaq also said similar problems plagued orders Friday for shares of Zynga (Nasdaq: ZNGA), the San Francisco game playing company that derives revenue from Facebook. Shares of Zynga also fell Monday, declining more than 4 percent but recovering to $7.09, down only 7 cents, by the close.

Monday's plunge knocked about $32 billion from the value of Facebook, whose shares Friday valued the company at $105 billion. It also knocked about $2 billion from the value of CEO Mark Zuckerberg's personal wealth. Before his marriage on Saturday, the 28-year-old CEO's stake in the company was valued at $18.9 billion.