How do you explain the 65% move since an absolutely terrible Q on every front? It is because it is even more clear now then ever they need capital, and they need it bad very fast. I am not saying they are not a good company, not even saying they might not be a giant. But they are already trading at 7.5x sales, 27x book, and 175x 2016 PE and facing massive share dilution shortly. This thing is priced to perfection for sales 5 years now that may not materialize. Only upside is to hope the over exuberance continues. And that is why I don't short it - because that over exuberance could continue.
You cannot short growth stocks with negative cash flow and a horrible balance sheet. These are the stocks that are controlled by the banks because they need debt and add-on offerings - the most lucrative business for banks. The stocks are propped up by sell-side analysts and trading desk support such that they look healthy at debt time. This is exacerbated by shorts, as they are easy prey to sell low and force to buy back high.