You can offload it to someone else. Say you shorted 100 shares at $50, but the price later goes to $100. One way to exit the short is to buy 100 shares on the open market, taking a loss of $5000. You can also find someone who wants to short, pay them $10,000, and transfer the position to them. Now the short position is off your hands, and the other person effectively entered into a short position at $100. It's kind of like taking over a lease.