It isn't listed as short able at IB, they are usually the best choice. I don't short frequently, not really a fan, but watch the supply at IB to get a feel, plus, have some friends that work there and communicate with them throughout the week. This thing erupted on the "Bitcoin" excitement. I jumped in and out quickly, just watching now. But, the whole segment has been nuts lately. Reminds me a little of the MJ craze, similar tag line trading. Good luck.