reminds me of the antics I used to observe on liquid stocks like sunw. It looked like the computer based traders would buy when everyone was selling and sell when they were buying. I bet it is some computerized system. Some nerd on the way to blowing up his firm... or, getting insanely rich.
I bet he is doing it for fun. Just to see if it does anything... I know i've done it before. Also, he may have been showing a huge offer but was slowly accumulating on the buy side, bidding it up till it hit a certain price, then wham he lets momentum players take him out. Metoox, how much depth does realtick show?