My first real job after college was at a Fortune 500. The stock price was very low and many of the older folks who I worked with were lamenting the fact they weren't retired yet. They had most of their retirement in company stock and they had not reached their number.
They had accepted a significant amount of risk by tying their retirement and current income to a single company's performance. I decided early on that I would not buy any company stock. The company stock has increased by a factor of 15; I've lost out on close to $250,000 in gains.
Yes, it would be nice to have that extra in the bank, and I chuckle to think about it. But, after seeing my coworkers who wanted to retire sit and work for an extra decade, I'm still glad I made the choice I did. I've started to look closer at the Employee Stock Purchase Plan, but only as a quick-sell strategy.
-Wings