Most stock grants to employees are at a particular locked in strike price and they can't sell for 6 months or so anyway. So their "buy" price as already set an

Most stock grants to employees are at a particular locked in strike price and they can't sell for 6 months or so anyway. So their "buy" price as already set and their "sell" price was going to be set by the market anyway. This is the only time FB can set the price. Any later sales of shares will be market priced.