Futures price does not refer to the pre-determined transaction price on futures contracts, but refers to the market price of futures (such as gold) that changes constantly with time.
I've always wondered why futures prices fell when Mark stared at the market, but people who held futures contracts were hurt. According to the futures return = ST-K. If the futures price is understood as ST, it can be understood.
So I think the futures price is not the price stipulated in the contract, but will become the market price (for example, with the gold market price).
I don't know if it's right!