I guess I grasp the concept of buy low, sell high, however, if you sold at 3.90 and bought back in at, say, 3.80 (or even 3.75) on few thousand shares you turned a profit of a few hundred dollars. I suppose you could keep doing that and make some nice profits w/ block of your shares but isn't that illegal? I thought you could not buy back into a stock you sold for 30 days?
Anyway, if you are a day trader (and this stock certainly swings enough to allow for it) then good luck.