the specific methods of short trading are as follows: ① pure speculative short trading. Traders do not own specific stocks themselves, but borrow stocks directly from others or through their securities companies for delivery. The purpose of its transaction is purely to obtain the difference income. 2 arbitrage short trading. Traders use the price difference between stock markets in different places to borrow from the lower-priced market, then sell it in the higher-priced market, and then buy it back when the price falls, so as to obtain the difference profit. (3) Short-selling with safe deposit box as the background. Its basic feature is that the trader owns the stocks engaged in short trading, but still borrows the same stocks from other sources for delivery. There are three other situations: one is that traders own stocks, but these stocks are stored in safe deposit boxes of banks or other special custody institutions, and it is not easy to take them out at the moment. In order to seize the trading opportunity, they borrow from other sources first and then make up for it later; The second is that traders own their own shares, but in order to postpone the tax payment for the current year, they sell the shares at the end of the year (usually in December) and buy them back immediately in January of the next year, thus delaying the tax payable to the next year; The third is that the trader owns a variety of stocks, and when he estimates that one of them is bearish, he sells it short and borrows the same stock from other places for delivery. If the market price does fall, he can use the profits gained as a short position to offset the losses of other stocks. And if the market price does not fall as expected, he can use the profits of other stocks to offset the losses of short trading. (4) hedge short trading. Traders have an excess position in a stock, that is, they buy more than they sell and are in an "overbought" position. However, the market trend of these stocks tends to decline again, so they engage in short-selling of other stocks in order to obtain profits from them to compensate for the possible losses of excess positions.

The main characteristics of characteristic long-term trading are as follows: ① Most of the funds needed by traders to buy stocks are lent by securities companies; (2) Different from ordinary commodity trading, the whole process of long-term trading can only be completed through the second transaction of buying stocks first and then selling them.

The main characteristics of short-selling are as follows: ① The stocks sold by traders are borrowed from securities companies, not owned by them; (2) general commodity trading is to buy first and then sell, and the transaction is completed at one time, while short trading is to sell first and then buy. The whole trading process consists of the second transaction of selling and buying.