If you bought at 2.30 and can sell at 9.10 then I'd agree that folks should seriously consider taking some profit. After all a bird in the hand....
But very few people have their shares at 2.30. More have them at 3 or 3.5 or 4.....and many many many more have some sort of mix. Myself I first bought the stock a good while ago. I bought again at 13 something and again at 8 something and again at 3.50 and then basically had no more money to invest in PLD.
So I have an average price now of 9.18. And I'm not selling. Do I think the stock will get back to 40 or 50 anytime soon? No. Do I believe the stock has the potential to get to 20-25 or upper 20's in two years. Yes I do. Management has to continue to strengthen the balance sheet, rent properties, and pay the 2009 dividend as promised. That could get them to 12-15. Then in 2010 a raising of the dividend and beginning to do development should move the stock up into the 20's. All of that is easier said than done, but it isn't a far-fetched scenario in my view.
So if you believe my view and bought 10,000 shares at 2.30 maybe you sell 4000 shares to pocket some money and keep 6000 shares and aim for 24.75.