@moowee, what I was attempting to explain was that short sellers...

@moowee, what I was attempting to explain was that short sellers both buy and sell the stock they are shorting in order to control the price.They control the volatility and play both sides of the market. Selling short involves costs of borrowing but it also has a major advantage over the longs in that every time a short seller sells a borrowed share he gets the cash credited to his account which offsets the margin required to maintain the short position. If the market is moving against his short position and a margin call is looming, he can either buy back the short share and take the loss or, if he still has enough firepower he can sell more at the higher price both forcing the price down and increasing his cash position at the same time which improves his margin account and the risk of a squeeze. That is why we see apparently illogical trading when the shorts decide to "pile on" and the longs have run out of funds to oppose them.