[rbcgerard]

Usually the major problem with buying employee shares on the secondary market is information asymmetry - the company is not going to provide the buyer with any information, therefore unless the buyer is intimately familiar with the inner workings of the company (I.e. An investor, or incredibly well plugged in) they really have no idea how the company is doing (despite being a "hot" company) which in turn makes it incredibly difficult to come up with market clearing prices

[wyman]

That's definitely true - so basically, the buyer is more averse to buying especially considering they are essentially investing in the dark, going off of public news or hearsay? For some of the most-fundraised private companies e.g. Uber, Airbnb, Stripe etc. I figure many would be satisfied with the last private round valuation or a small discount, and the loss/market inefficiency here (5-10%) would still allow most deals to work. However, as a seller, your pitch, especially for less-well-known companies, would be much more difficult.