Peter Thiel sold 20 million shares of Facebook just months after its IPO—but they’d be worth nearly $15 billion more if he had held on

Billionaire Peter Thiel was Facebook’s first outside investor, but he may now have regrets for how soon he cashed out. Just months after the tech company’s IPO, he sold millions of shares for $20 each for a sum of $400 million; with the stock now worth 37 times more, he could have been $15 billion…