Futures is a trading method that spans time. By signing the contract, the buyer and the seller agree to deliver the specified quantity of spot at the specified time, price and other trading conditions. Futures are concentrated in futures exchanges and traded through standardized contracts. Some futures contracts can be traded through over-the-counter trading, which is called over-the-counter contract. According to the types of subject matter, futures can be divided into commodity futures and financial futures. The future in English is the future, which evolved from the word "future". It means that both parties to the transaction don't have to deliver the physical object in the early stage of the transaction, but agree to deliver the physical object at some time in the future, so China people call it "futures". Futures is the largest means of trading besides foreign exchange.