Shares in social networking giant Facebook have fallen 3.8 percent as the company allowed employees to start selling some stock.
Staff were meant to be able to sell their vested shares on Monday, but US markets were closed for two days due to storm Sandy.
The BBC quoted Michael Pachter, an analyst at Wedbush Securities, as saying that Facebook had timed its "unlocking" badly.
"I don't really understand why Facebook [chose] to unlock virtually all of its compensation within the year of its IPO (initial public offering), but they did," Pachter said.
"They made a mistake and set the company up for volatility," he added.
Facebook had suffered a painful public debut earlier in 2012, as investors worried about the firm's ability to keep up revenue growth.
The firm's shares, which began trading at 38 dollars in May, have since lost about 50 percent of their value.
According to the report, they closed at $21.11 on Wednesday. (ANI)