I'm going to side with roadstress here - just because I run an large mining operation that doesn't mean i'm cashing out to fiat right away - perhaps I DONT want to flash crash everything so I have an incentive to sell it slowly at an average pace - keeping a large chunk for later. 

I think the end-game for BTC happens when we all aggressively leave BTC because a new system occurs that has higher monetary incentive than bitcoin, with current gen asic hardware.  So far as I can tell, nothing on earth could disrupt BTC's place unless a country is willing to go so far as to actually back a new type of cryptocurrency that can use existing POW sha256 mining power and can back real world value like current fiat - that is unlikely to happen though as no practical national leader would take such a great risk on a new experimental technology.  Could you imagine the countless deviants trying to 51% it?