For me its quite simple to understand what is happening, its not "free" to become part of the traditional market, and when you become part youa re gonna start experiencing the bad things about him, for example market manipulation or forcing positions because they have more quantity/force to move in one direction or another.

And that is what they are doing right now, they are selling some and waiting to the price drop a little and rebuy again below the start price. That mixed with miners taking profit, rumours of some BTC coming from MTgox made this pressure in the sell book.

But nothing dificult to overcome, we have time and true in our side, just HODL.