NDF refers to non-delivery forward foreign exchange transaction, which is a kind of forward foreign exchange transaction, a typical OTC product, and an offshore product in essence. Banks act as intermediaries. Based on different views on the exchange rate, the two parties sign a non-deliverable forward contract to determine the forward exchange rate. When the contract expires, only the difference between the contract exchange rate and the actual exchange rate needs to be delivered according to the transaction amount, and there is no need to deliver the principal involved in the transaction. The settlement currency is freely convertible, mostly settled in US dollars, and the main terms are 1W, 1M, 2M, 3M, 6M and 65438. NDF is mainly used in the currencies of countries that implement foreign exchange control, and NDF transactions such as RMB, Korean won and new Taiwan dollar are more active in Asia.