Buying refers to the behavior of investors in the financial market, because they are optimistic about a product, stock, futures, currency and so on. And think that its short-term or long-term market is bullish, so buy a stock, futures or currency. Traders expect the future price of foreign exchange market to rise, buy a certain amount of currency at the current price, and hedge the contract position at a higher price after the exchange rate rises for a period of time, thus making a profit. This way belongs to the trading mode of buying first and selling later, which is just the opposite of short positions.
Put option, also known as "put option" or "knock out option", is the right to sell a security at an agreed price and quantity within a certain period of time. One of the types of option trading is the symmetry of call options. After buying a put option, the customer has the right to sell a certain security to the buyer of the option at the price and quantity specified in the contract within the specified date or period.
Arbitrage is also called "interest arbitrage". There are two main forms: (1) no arbitrage. That is, using the interest rate difference between the capital markets of the two countries, short-term funds will be transferred from the low interest rate market to the high interest rate market to obtain spread income. (2) arbitrage. That is to say, the arbitrageurs use forward foreign exchange transactions to avoid the risk of exchange rate changes while transferring short-term funds from place A to place B for arbitrage.