[sneo]

hsi options expires one business day before the futures. settlement price used is the futures expiration settlement price (average of HSI at every 5min interval on the last day). if ITM, options become futures on the last day and then settled as futures, else, it disappears forever.

hence, while the settlement price is the same for the option and futures, the need to specify if it is option or futures affects the actual settlement. The options go worthless if OTM and hence end of story; for futures, we still need to determine who receives or pays because its a obligation.