Long and short is a term in the trading market, which is used to describe the expectations of market participants for the future price rise and fall of a trading product. "Going long" generally refers to being bullish, that is, holding long positions in anticipation of rising prices, and participants are called going long or multi-party. A long position refers to a position in which market participants hold a buying contract for a certain trading variety. "Empty" generally refers to short selling, that is, holding short positions in anticipation of price decline, which participants call short or empty. Short position refers to the position where market participants hold the selling contract of a certain trading variety.

Both bulls and bears are participants in market transactions, and their trading behavior also affects the price trend of the market.