I learned long ago (when my company decided they couldn't give me options because we were too big so they did these "I can't believe it isn't an option", which expired worthless): until cash is in my bank account it is just a promise waiting to be broken. If I want to invest I want it my choice.

In any case, it is a bad idea to invest in the company you work for - unless you are high enough up in the company that you see the real books, or you have so much invested they have to show you as a large shareholder. (nobody is the later - large shareholders have a full time job managing their money not working for someone else). There have been a number of cases where a company has unexpectedly filed bankruptcy and someone lost their job and their savings on the same day.