The danger is a whale can buy short futures. Then he sells all his bitcoin. The price crashes as other sellers exit, he covers his shorts and buy back all his btc. This is how markets are manipulated with futures. And it's about to happen with btc. Bitcoin has been free of wall street manipulation until now.
You have been warned!
And where are they going to get the huge amounts of bitcoin to sell short and crash bitcoin. ? From the exchanges ! Remember big exhanges restrict withdrawals and they signed the New York Agreement for sw2x. ie.They have indicated their desire for centralized control.
People MUST get their coins off all exchanges!
I don't get it. How would taking your coins off exchanges impact this directly? The CME Bitcoin futures are supposed to be cash-settled and marked-to-market daily. Nobody, neither the CME nor the market participants, need to hold a single bitcoin for the whole thing to work. Market participants would probably put up margin in cash and not bitcoins. They may hold bitcoins externaly to hedge, but that is not required.
Because if you manipulate the markets it's essential that you co-ordinate the movement of both markets in the same direction , for max effect. No use selling the futures market and the bitcoin market moves in the other direction. It may move opposite in any case , but they may attempt to time the move in both markets for max effect. The futures market is just a sentiment magnifier.
Also, who knows, they may attempt to set the bitcoin price in the futures market. Making it "official". As they do with gold. The gold spot market has been hidden from public view.