Short buyer
A short buyer is a trader who buys to close a short position. Short buyers are often obliged to buy when the market makes them, which makes them the most aggressive buyers in the market.
A short can only close with a buy, so when price rises through the shorts’ stops and liquidations, they must buy at any price. That forced buying is what powers a short squeeze. Short buyers push price up, together with long buyers.
Learn more: the four market players.