Shorting any financial asset is a valid and usually very risky speculative strategy. In the case of gold, it needs a massive amount of money and, in order to negate the risk, zero fear of losing that money. The only entities that are in that position are central banks. But aside from governments and banks, who else would be interested in driving down the price of bitcoin to the extent that it might ultimately kill off the golden goose? And more importantly, who else would have both the money/means and motive to do so? This feels more like a slow and steady attack on bitcoin's core rather than shorting for long term profit. Perhaps I'm being paranoid.