Read more Investment in securities provides an important channel for the society to raise funds, which is an effective way for enterprises to raise direct financing. Including ambulances, fire engines, sanitation vehicles, TV and radio cars, airport operations, municipal construction projects, etc. In economic terms, the benefits of holding any two currencies should be equal in the equilibrium of the foreign exchange market, which is: Ri=Rj (interest rate parity). Here, R stands for yield, and I and j represent currencies of different countries. If the benefits of holding two currencies are unequal, you will have A arbitrage: buy A kind of foreign exchange and sell B foreign exchange.