We give employee stock options. Naturally at a given time, some of the options are vested, some are not. If company is sold for cash, how do we make sure: (1) vested portion (which we plan to give employee net gains) does not incur immediately (we want employees to get long term capital gain tax vs. income tax)? Should we hold these in a trust? (2) For unvested portion, assume we have $ to give it (eventually) to employee, how can we "simulate" vesting process and also get employees favorable capital gain tax treatment?