There actually aren't a whole lot of homes on the market (much of the city's housing stock is either rental properties or is owned by longtime residents who ain't moving anytime soon), but to answer your question: anyone who's been at Google, Apple, or Facebook since 2009, got stock options, and held them. Google stock has appreciated 7x since then, Apple 10x, FB a whopping 35x. $100K in stock options is actually a pretty small options package over 4 years, but if you got that much in FB stock when the whole company was worth $15B, that's now worth $3.5M.