New regulation requirements force the shorting HF's to lower their risk on paper by buying shares. That is not covering, that is not a margin call, that is not a forced buy-in. They are simply required to hold a percentage of the stock they are shorting. As soon as they purchased shares, they have more shares to (covered) short in addition to the shares they are borrowing. Think of it from their perspective. They are spending as little money as possible to get the maximum drop in stock price, kicked down the road as far as they can. Don't underestimate billionaire crooks who hire entire teams of literal rocket scientists that all depend on this to "work out" in their favor. They will go down fighting, clawing, screaming, and ultimately crying in futility. We're only now entereing the clawing stage.