1, deal. A company that buys foreign assets is not allowed to trade in its own currency, so it requires the buyer to convert its own currency into the currency of the country where the assets are purchased. This is one of the reasons for the formation of the foreign exchange market.

2. speculation. There is a certain exchange rate between one currency and another, which will change with the change of supply and demand between the two currencies. A trader buys a currency at this exchange rate and then sells it at another exchange rate that is stronger for him. At this time, he got the profit after the exchange rate changes.

3. hedge. Because of the exchange rate fluctuation between different currencies, investors also have certain risks when converting one country's currency into another. In this case, the company can eliminate this potential profit and loss through hedging transactions. In other words, investors execute a foreign exchange transaction on the basis of the previous transaction.