I have some understanding of this content. Let me answer your question. This is a term in futures trading. Futures trading implements a two-way trading mechanism, which is available to both buyers and sellers. In futures trading, buyers are called bulls and sellers are called bears. Although the buyer is also called a bull market in the stock market, the seller is called a bear market. But the seller in stock trading must be the person who holds the stock, and the person who does not have the stock cannot sell it. 9 16