Rule of thumb. Never falls in love with any stock but rather fall in love the gain that it will do. If you ask what price than you need to look deep inside as what is your goal fromf the stock as per exit price and entry price before you get into the stock. Time is on your side if you take advantage of it which means get in when you see value and get out when you see too much froth which is hard some times as greed get into your mind to hold on longer than it should be.
Don't sweat it. I made 70k on fslr and still holding 20%. I have not sold spwr but rather load up on any pull back. I am up about 100k on it. so if I am confident so should you. My avg on fslr was 15.5 and spwr 9/10 range. just load some more on 23.96. Target 30 for this baby.
This can work for you if you buy in and out. I have make over 10k on this company by get in at 14-15 and sell 16-17. I think I'd four times already this year and not to mention previous year and on so... Long Term investment is tougher now since we are in the age of information which means things can happens very quickly thus you can want to re-think your long position. Another point of view.