Facebook director Peter Thiel unloads shares in the social network

This is big. Facebook director and early investor Peter Thiel has unloaded the majority his stock in the social network.

According to CNBC, Thiel sold around 22-million of Facebook shares. Although he did so at the first possible opportunity, it was reportedly in keeping with a plan he had formulated prior to the company going public.

That means Thiel’s decision to unload so many shares was not in reaction to Facebook’s stock market woes over the past few weeks. It’s not exactly uncommon for angel investors to unload their shares as soon as possible either.

An attorney told CNBC that Thiel could have changed his mind on selling his shares if he wanted, but that it would have been complicated. The switch would have to happen in an open trading period and the angel investor would have to confirm that he didn’t have any material non-public information. Thiel’s position on the board could complicate that.

That said InsiderScore.com’s Director of Research Ben Silverman thinks it might not have been as difficult as some are making out:

“The purpose of Rule 10b5-1 plans is to provide an affirmative defense, but not safe harbor, against insider trading allegations,” Silverman said. “For someone to be guilty of insider trading, an actual trade has to be transacted. As such, the cancellation of a plan would not be an insider trading offense because the action would result in no trade, thus no punishable offense, occurring.”

Thiel will retain five million shares in Facebook as well as his position on the board. He’s also joined by Microsoft, which sold about 20% of its stake in the company.