Does futures have the function of locking in costs?
Yes, for example, after 1 month, you need 10 tons of rebar. Now the price is 4000, but you predict that the price will rise in the future. In order to lock in the cost, you buy 1 hand rebar futures contract in the futures market. A month later, futures rose to 4,500 yuan/ton, you earned 500 yuan/ton in the futures market, and rebar also rose to 4,500 in the spot market. Then the spot cost of buying rebar is locked at 4000. However, if the spot of rebar falls to 3500 in the later period, the futures will lose 500 and the spot will earn 500. The two are still offset, so the cost cannot be reduced.