期权，又称选择权，它是一种权利合约，给予其持有者在约定的时间内，或在某一时间之前的任何交易时刻，按约定价格买进或卖出一定数量某种资产的权利。该资产称为基础资产，在期权合约中所规定买进或卖出基础资产的价格称为期权的履行价。期权的最后有效日期称为期权的到期日 An option, also known as an option, is a contract of right that gives its holder the right to buy or sell a certain amount of an asset at an agreed price, at an agreed time, or at any trading time prior right. The asset is called the underlying asset. The price at which the underlying asset is bought or sold in an option contract is called the strike price of the option. The last effective date of an option is called the expiration date of the option