Funds have broad and narrow definitions. Fund in a broad sense is the general name of institutional investors, including trust and investment funds, unit trust funds, provident funds, insurance funds, retirement funds and funds of various foundations. Funds in the existing securities market, including closed-end funds and open-end funds, have the characteristics of income function and value-added potential. From the accounting point of view, capital is a narrow concept, which refers to funds with specific purposes and uses. Because the investors of government agencies and institutions do not require investment returns and investment recovery, but require funds to be used for designated purposes in accordance with the law or the wishes of the investors, funds are formed. The funds we are talking about now usually refer to securities investment funds. The concept of foreign exchange has a double meaning, that is, there are dynamic and static points. The static concept of foreign exchange is divided into narrow foreign exchange concept and broad foreign exchange concept. In a narrow sense, foreign exchange refers to various means of payment expressed in foreign currency, which are generally accepted by all countries and can be used for international settlement of creditor's rights and debts. It must have three characteristics: affordability (assets that must be expressed in foreign currency), availability (claims that can be compensated abroad) and convertibility (foreign currency assets that can be freely converted into other means of payment). Foreign exchange in a broad sense refers to all assets owned by a country in foreign currency. The International Monetary Fund (IMF) defines this as: "Foreign exchange is the creditor's rights held by monetary management authorities (central bank, monetary management institutions, foreign exchange stabilization fund and the Ministry of Finance) in the form of bank deposits, treasury bonds and long-term and short-term government securities. It can be used when there is a deficit in the balance of payments. " China's Regulations on Foreign Exchange Management, revised and promulgated in 1997, stipulates: "Foreign exchange refers to the following means of payment and assets expressed in foreign currencies that can be used for international settlement: (1) foreign currencies, including coins and banknotes; (2) Foreign currency payment vouchers, including bills, bank deposit vouchers and postal savings vouchers; Foreign currency securities, including government bonds, treasury bonds, corporate bonds, stocks, coupons, etc. ; (4) Special Drawing Rights and European Monetary Units; (5) Other foreign exchange assets. " The dynamic concept of foreign exchange refers to the flow of money between countries and a specialized commercial activity of exchanging one country's currency for another to pay off international creditor's rights and debts. It is the abbreviation of foreign exchange.