Arbitrage: buying and selling two different futures contracts at the same time Traders buy contracts that they think are cheap, and sell those high-priced contracts at the same time, benefiting from the changing relationship between the prices of the two contracts. In arbitrage, traders are concerned about the mutual price relationship between contracts, not the absolute price level. Arbitrage can generally be divided into three categories: intertemporal arbitrage, cross-market arbitrage and cross-commodity arbitrage. Intertemporal arbitrage is one of the most common arbitrage transactions. When the normal spread between different delivery months changes abnormally, it is profitable to hedge the same commodity, which can be divided into two forms: bull spread and bear spread. For example, in the metal bull spread, the exchange buys metal contracts in the latest delivery month and sells metal contracts in the forward delivery month, hoping that the recent contract price will rise more than the forward contract price; Bear market arbitrage is the opposite, that is, selling the recent delivery monthly contract and buying the forward delivery monthly contract, expecting the price drop of the forward contract to be smaller than the recent contract. Cross-market arbitrage is an arbitrage transaction between different exchanges. When the same futures commodity contract is traded in two or more exchanges, there is a certain price difference relationship between commodity contracts due to geographical differences between regions. For example, London Metal Exchange (LME) and Shanghai Futures Exchange (SHFE) both trade cathode copper futures, and the price difference between the two markets will exceed the normal range several times a year, which provides traders with opportunities for cross-market arbitrage. For example, when LME copper price is lower than SHFE, traders can buy LME copper contract and sell SHFE copper contract at the same time, and then hedge and close the trading contract after the price relationship between the two markets returns to normal, and vice versa. When doing cross-market arbitrage, we should pay attention to several factors that affect the spread of each market, such as freight, tariff and exchange rate. Cross-commodity arbitrage refers to trading by using the price difference between two different but related commodities. These two commodities can replace each other or be restricted by the same supply and demand factors. The form of cross-commodity arbitrage is to buy and sell commodity futures contracts with the same delivery month but different varieties at the same time. For example, metals, agricultural products, metals and energy can all carry out arbitrage transactions. A simple example is borrowing money at a lower interest rate and borrowing money at a higher interest rate. Assuming there is no risk of default, this behavior is arbitrage. The most important thing here is the identity of time and the certainty that the income is positive. In reality, there is usually a certain time sequence, or a small probability of loss, but it is still called arbitrage, mainly in a broad sense. Generally speaking, arbitrage is the operation of buying low and selling high at the same time! At present, in the securities market, arbitrage that has been recognized by everyone includes ETF arbitrage, securities transfer arbitrage, convertible bond arbitrage, warrant arbitrage and so on. (The above is the whole content of this article. )