I think this is probably the most difficult situation as it's extremely hard to predict if the stock will become liquid. At this point one should be looking ei

I think this is probably the most difficult situation as it's extremely hard to predict if the stock will become liquid. At this point one should be looking either at solid financials or a twitter like ability to command a great valuation. I think Square and Dropbox both have solid rev models and valuations, my guess is that both would experience a liquidity event in the next 5 years.