I usually sell everything as soon as I can. It was best when I was able to sell immediately; a 15% return on ~1.5 months investment time? I'll take as much as I can and happily pay the tax on it.

Sadly, they now have us locked in to a 1 year minimum holding period, which sucks. I had still been selling everything as soon as I could, but the return is no longer guaranteed because the price can drop in that time.

Our stock dropped a while back to what I consider below market value and so I have been holding while the price has slowly come back up. The good news is that everything I've bought since then has been really cheap, but I'm now holding far more of my company's stock than I would like as a share of my portfolio.

I think we've just recently gotten back to fair value, so I'm starting to think about selling. I've also been selling covered calls along the way, so I have at least gotten a little extra income while holding.