They set a post-IPO low of $18.23 in early Friday trading, before recovering to $18.35, down $3.87, bringing the loss on investors who paid $19 in the IPO to nearly 52 percent.
After the lockup period on insiders expired, Peter Thiel, an early backer, as well as co-founder Dustin Moskovitz sold more than 21 million shares of Facebook, of Menlo Park, Calif.
Since the insider sales began, Facebook shares have traded no higher than $19.73.
![Singapore Supervisor Slaps Intern To 'Nurture' Him In Viral Clip [VIDEO]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_thumbnail/public/2013/05/21/singapore-supervisor.png "Singapore Supervisor Slaps Intern To 'Nurture' Him In Viral Clip [VIDEO]")
![Fort Worth Texas Tornadoes Claim 6 Lives: Pictures And Videos During The Storm And Its Aftermath [PHOTOS/VIDEO]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/05/16/tornado.PNG "Fort Worth Texas Tornadoes Claim 6 Lives: Pictures And Videos During The Storm And Its Aftermath [PHOTOS/VIDEO]")
![Introducing Skywhale: Canberra, Australia’s Controversial $300K Centenary Balloon [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/05/14/skywhale.jpeg "Introducing Skywhale: Canberra, Australia’s Controversial $300K Centenary Balloon [PHOTOS]")
![Meet Ahmed Angel: The Greatest Internet Superstar. Ever. [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/05/14/ahmed-angel.jpg "Meet Ahmed Angel: The Greatest Internet Superstar. Ever. [PHOTOS]")
![Airbus Shows Off The First A350 XWB, The Boeing 787's Rival [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_multimedia/public/2013/05/13/a350.jpg "Airbus Shows Off The First A350 XWB, The Boeing 787's Rival [PHOTOS]")
![Lisalla Montenegro: Meet Angels Pitcher C.J. Wilson’s New Supermodel Fiancé [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/05/10/lisalla-montenegro_3.jpg "Lisalla Montenegro: Meet Angels Pitcher C.J. Wilson’s New Supermodel Fiancé [PHOTOS]")
![Surviving Sandy: The Rockaways Rise From The Ashes Six Months Later [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/05/09/breezy-point_4.JPG "Surviving Sandy: The Rockaways Rise From The Ashes Six Months Later [PHOTOS]")
![Tsarnaev Friend Killed In Orlando By FBI, Ibragim Todashev Shot Day Of Planned Trip To Chechnya [PHOTO]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_small/public/2013/05/22/ibragim-todashev.jpg "Tsarnaev Friend Killed In Orlando By FBI, Ibragim Todashev Shot Day Of Planned Trip To Chechnya [PHOTO]")
Like or Follow us for updates on the biggest stories!