Seagull option is a complex trading strategy. Let's take foreign exchange options as an example to illustrate. Seagull option involves three options, and the enterprise needs to buy $6,543,800+0,000 in foreign exchange from the bank after three months. First of all, the enterprise needs to sign a foreign exchange call risk reversal option portfolio with the bank (the name of China Bank is Interval Bao, and other banks also have different names), and the interval is [6.6000, 6.7000], that is, to buy a foreign exchange call option with a higher exercise price (6.7) and sell a foreign exchange put option with a lower exercise price (6.6), and the total expense of the two options is 0. So far, people have three choices. Let's analyze the possibility range and profit and loss of the market exchange rate one by one after three months. After the expiration, if the exchange rate is lower than 6.6, the put option of selling foreign exchange will be executed, and the exchange rate of purchasing foreign exchange will be 6.6 yuan. After deducting the option fee, the actual cost of purchasing foreign exchange is 6.58. If the maturity exchange rate is [6.6,6.7], the above three options, namely the market exchange rate (minus 200BP), will not be implemented. When the market exchange rate is [6.7, 6.8], only one option is executed, that is, the foreign exchange call option with the execution price of 6.7, and the actual foreign exchange buying exchange rate is 6.68 (6.7-0.02). When the market exchange rate is (6.8,+infinity), two options are executed, one is a newly executed put foreign exchange call option with an execution price of 6.8, and its foreign exchange buying exchange rate is the market exchange rate minus 0. 1200( 1200BP). I wonder if my answer is satisfactory. I work in a bank and deal with import and export customers every day. There are many good cases that can be discussed if necessary.