Swap agreement, also known as swap contract, is a kind of contract signed by both sides of internal transaction to exchange certain assets with each other in a certain period of time in the future. He said, more accurately, a swap contract is a contract signed by both parties to exchange cash flows that they think have equal economic value in a certain period in the future. The specific exchange objects can be different kinds of currencies and bonds, as well as different kinds of interest rates, exchange rates and price indexes. Generally speaking, the two parties to the transaction (sometimes more than two traders participate in the same swap contract) agree on the payment rate (exchange rate, interest rate, etc.). ) according to the market situation, pay each other on the basis of determining the principal amount. The difference between swap contracts, futures contracts and option contracts is that swap contracts are generally non-standardized and cannot be listed and traded like futures contracts and option contracts.