The so-called futures generally refers to futures contracts, which are standardized contracts made by futures exchanges and agreed to deliver a certain number of subject matter at a specific time and place in the future. This subject matter, also called the underlying asset, is the spot corresponding to the futures contract. This spot can be a commodity, such as copper or crude oil, a financial instrument, such as foreign exchange and bonds, or a financial indicator, such as three-month interbank offered rate or stock index.

When shorting, that is, selling first and then opening a position, it means that after paying a certain margin (trading margin), the trader holds the contract of selling goods in his hand and buys and closes the position when the price falls, not only closing the contract in his hand, but also automatically transferring the paid margin back to your trading account. This completes a trading process, and the price difference is the profit you get.