Facebook angel investor Peter Thiel has sold around 20 million shares in the company, netting a cool US$400 million.
The lock-up period, which prevents inside investors from selling shares too close to an initial public offering (IPO), expired last week. Facebook held its IPO in May.
The sale of the shares followed a trading plan adopted in May, according to a US Securities and Exchange Commission (SEC) filing, when the company first went public at US$38 per share.
Despite Facebook's current lower share price, the sale amount, at between US$19.27 and US$20.69 per share, was a far cry from the US$500,000 that Thiel invested back in 2004. Thiel had already sold 16 million shares during the company's IPO, and still retains some shares in the company.
Thiel was Facebook's first external investor. He also co-founded PayPal. Recently, he made his first investment in an Australian start-up: he led an investment round in ScriptRock, which tests companies' systems to check whether they are configured correctly.
The news came as reports surfaced that Microsoft had also sold 20 per cent of its stock in Facebook at the time that Facebook went public, receiving US$249 million for the sale.