In early futures trading, because there was no computer, open outcry was used in trading. There are usually two forms of public bidding: one is continuous bidding system (moving disk), that is, floor traders openly bid face to face in the trading pool of the exchange to express their requirements for buying or selling contracts. This bidding method is the mainstream of futures trading, which is adopted by European and American futures markets. The advantage of this method is that the atmosphere of the venue is active, but the disadvantage is that the scale of personnel is limited by the venue. The trading pool is crowded with so many traders that they have to use gestures to help convey trading information. Another disadvantage of this method is that floor traders have more information and time advantages than OTC traders. Hat-grabbing transactions often become the patent of floor traders.

Another form of public bidding is the one-price system in Japan. The one-price system divides each trading day into several intervals, and each interval has only one price for a contract. First of all, the host bids for each transaction, and the floor traders declare the buying and selling quantity according to their own bidding. If you buy more than you sell, the owner will quote a higher price. On the other hand, quote a lower price until the number of transactions between buyers and sellers is equal at a certain price.

After the popularization of computer technology, exchanges all over the world have changed their ways and adopted computers instead of the original open bidding method. Computer matchmaking transaction is an automatic transaction method designed according to the principle of open bidding, which has the advantages of accuracy, continuity, high speed and large capacity. At present, all futures exchanges in China adopt computer matching trading methods.