When the prices of buyers and sellers are right, futures are automatically traded, and so are stocks. Futures exchanges buy and sell standardized contracts, in which the quality, quantity, delivery place and payment terms of goods are standardized, and only the price of goods changes. Futures trading is based on "hands", such as soybeans, 1 hand is 10 ton. If you want to buy 100 tons of soybeans, it is a 10 lot soybean contract in the futures market.