Good luck with shorting Bitcoin. In my opinion, it is too risky to trade at the beginning of introducing such important thing. We can't really tell what the investors will do. I wouldn't be surprised if they tried to force a huge dump and then they would buy BTC for a lower price. They could repeat this a few times and voila! It's basically free money for them. I don't want to lose my BTC so I won't risk. I won't trade.