For example, if you want to buy a TV set at 10000 now, but your money is borrowed from a friend and will be paid back to you after 3 months, and you are afraid that the price of the TV set will rise to 12000 after 3 months, you can sign a contract with the TV seller, buy it first and deliver it after 3 months, so you will pay a deposit of 1000 for it. But if the TV price drops to 8000 yuan in three months, you still have to buy it at 10000 yuan. Then you plan to lose 2000 yuan.