Different from stock index futures, stock index options have a very special point: the positions of stock index options will not decrease as the expiration date approaches. A large number of market participants need to deliver, so a simple and convenient delivery method of options is very important. The European option convention for cash delivery is not only an automatic exercise, but also meets the needs of participants for easy operation when making delivery.

Through the study of six markets in Europe, America, Hongkong, Taiwan Province, South Korea and India, it is found that the positions of stock index futures are decreasing with the approaching maturity date, while the positions of stock index options are mostly stable in the second half of the delivery month. By analyzing the reasons, there is a linear relationship between the return of stock index futures and the underlying assets, and the related trading and investment strategies are relatively simple. In the overseas stock index futures market, in order to hedge the risk of OTC products, a large number of institutions adopt DeltaOne strategy to hold stock index futures for a long time, and open positions in the current month's contracts, and extend them when the current month's contracts are nearing expiration, so as to achieve the purpose of long-term positions. Therefore, before the futures are due for delivery, the positions will suddenly drop. In contrast, the stock index option strategy is more dispersed, so the position is relatively stable near the maturity date.