Facebook stock has continued to decline after selling for $38 per share during its IPO. Yesterday shares fell below $19 during trading, but closed at $20 for an increase of around 5% before the 20.1 million share sale was disclosed by the SEC. Speculation surfaced last week that Thiel would shed stock in the social network after the expiration of the lockup agreement. That agreement prevented 271 million shares held by early investors and employees from being sold. Thiel still owns shares personally and has voting control over shares owned by Founders Fund. Forbes reports that Thiel personally grabbed about $285 million after taxes by selling off stock in Facebook. Thiel has been an investor in Facebook since 2004, when he offered $500,000 for over 10% of Facebook, still known as Thefacebook at the time. [ via Forbes]