Borrowed stock for the purposes of shorting is called the "float". Short sellers sell borrowed shares at a high price with the hopes of repaying them later at a lower price. If the price rises against them, they get trapped in the float and eventually have to buy shares to cover their debt. If a lot of people are in the float and you happen to own a few shares, you can ask a high price as those in the float have no choice but to buy and cover. When buyers in the float are depleted, the artificially high price will likely decrease.