At today's run rate it would take 19.5 days of volume for the shorts to cover the 3.9M shares short. This is money in the bank for the longs. They are toast. I think the shorts "shot thier wad" and ran out of money. Any attempt for them to cover will drive the price up substantially.
Besides the short covering that will take place, there is money on the sidelines that is ready to jump in once there is positive news. People may have underestimated how explosive the price run will be once we get a positive PR.