The exchanges could implement stop limits. But it is up to them. Dark pools are the big problem I think. They are hiding the real depth of the market. If big orders move the market, so be it.
So with dark pools you don't get to see the USD/BTC exchange that is being done right? Has anyone out there analyzed data from the block chain? I guess that wouldn't help shed any light on dark pools since you don't see the USD portion of the transaction right? How would one get in on a dark pool in mt. gox? Do the people in a DP get to see the ask & bid?