Tricky question that I'm not 100% sure on the answer of... My understanding is that it depends on the company, the stock agreement and of course finding a buyer. A company like foursquare is probably tough because there is such a risk of the stock being worthless. There are a lot of ways that I mentioned such that most common stock will become worthless, so all of that is factored in.

There's a good document on equity compensation that was recently posted to HN, it has a few notes on secondary markets: https://github.com/jlevy/og-equity-compensation#what-is-your...