As the name implies, butterfly arbitrage is like a butterfly, with wings symmetrical to both sides of the body. Three kinds of contracts in futures arbitrage are near-month contracts, forward contracts and more forward contracts, which we call near-end contracts, mid-end contracts and far-end contracts.

It is precisely because of the objective differences in the price levels of futures contracts in different delivery months, and with the changes in the relationship between supply and demand in the market, there may be a large price difference between the contracts in the middle delivery month and the contracts in both delivery months. This has caused arbitrageurs to be highly interested in butterfly arbitrage, that is, by operating butterfly arbitrage, using the futures contract spreads in different delivery months to hedge and close positions to make profits.