If this market isn't being manipulated then I'm a monekey's uncle. I've been watching it on and off all afternoon, and I keep seeing it move rationally (ie price changes are a function of the size of the trade) and then irrationally (sudden discontinuities on tiny trades). For example, I just watched it decline from ~126 to 115 over a few minutes, and then suddenly jump up by +10 on a 0.03 BTC trade. Maybe I'm misunderstanding the efect of lag here, but it looks shady as heck.

Edit: Also, spreads of over 10% among different markets? Yeesh.