Seems odd that they don't discuss a common reason to short a stock: you expect it to go down, without any real opinion on the business. In this case there is going to be a ton of new float fairly soon. It's a pretty safe bet that this will depress the price. So the natural trade is to sell now (short), and buy later (cover the short). That effectively moves the future price drop to "now", which is likely what we see. This is just one way (of many) in which the market factors future events into today's price, which is sort of the whole point.