On Wednesday, Facebook’s third lockup period expired and 777 million additional shares became eligible for sale, almost doubling the company’s float (the stock available to be traded in the public market).
When the first two lockup periods expired in August and in late October, early investors had taken the chance to sell shares and the stock price had consequently dropped.
So people were expecting the worse for Wednesday, as the number of shares released from trading restrictions was much larger this time.
Quite the opposite happened though: Facebook’s stock price climbed through the day and closed trading 13 percent above Tuesday’s closing price.
Apparently this time most insiders didn’t take the first chance to dump their shares and traders valued that as a good sign.
Facebook Avoids Crash After Third Lockup Period Expires

Description
This chart shows Facebook's stock price and trading volume since the company's IPO in May 2012.



















