Take steel futures as an example: the most direct difference between steel futures and electronic disks lies in the design of contracts. They are the same in the minimum change price, delivery month and delivery method, but they are quite different in the trading unit, margin and delivery level. The size of marketing unit is mainly determined by considering the market size of the subject matter of the contract, the size of the trader's funds, the spot trading habits of commodities and other factors. In view of the huge spot market and active trading of steel products in China, the futures market chooses 10 ton/lot, which is in line with the characteristics of steel products. The purpose of setting the daily maximum price fluctuation limit is to prevent the risks brought by excessive price fluctuation to investors. Generally speaking, the more frequent and violent the price fluctuation of the subject matter, the greater the price fluctuation limit should be set. From the comparison between the two, the price chosen in the previous period does not exceed 5% of the settlement price of the previous trading day, while the bulk steel transaction does not exceed the average price of 200 yuan/ton of the previous trading day. Judging from the trend of rebar price in China in recent years, the fluctuation is quite intense, so the percentage system is more flexible, and the daily price changes with the change of the settlement price the day before. When the price is at a relatively high level, the fluctuation space is correspondingly expanded, while when the price is at a low level, the fluctuation space is correspondingly reduced. At the same time, the percentage system enables trading orders to respond to changes in spot prices more timely and effectively. When the price of electronic transaction is high, it is beneficial to investors' risk control, while when the price is low, it is not conducive to investors' risk management. The transaction fee for futures contracts is not higher than two ten thousandths of the transaction amount (including risk reserve), while the transaction fee for bulk steel products is 1 yuan/ton. If it is converted according to the current price of rebar and wire rod, the bulk fee is cheaper. The difference between steel futures and electronic disk is not only reflected in contract design, but also in investor structure, market liquidity, legal supervision, transaction delivery and so on. First of all, from the perspective of investor structure. The participants of electronic disk are mainly steel-related enterprises, including producers, consumers and traders. It must be an enterprise legal person registered by the administrative department for industry and commerce, and must pay the seat rent to obtain the qualification of electronic disk distributor. There are not too many restrictions on the participants in the futures market. Not only steel-related enterprises can participate, but other enterprises, including private equity institutions, and natural persons can also become traders in steel futures. Any individual or enterprise can participate in steel futures trading as long as it meets the relevant qualification requirements of national futures trading, and does not need to pay the seat rent, and only needs to open a futures trading account in a legitimate futures company. Secondly, due to the different investor structure, the liquidity of electronic disk and futures market is also very different. Because only spot enterprises participate in electronic disk, and they are all regional, the liquidity of electronic disk is poor and the transaction volume is generally low. The futures market is a national market with a large number of speculators, which not only provides sufficient liquidity for the market, but also makes it easier for enterprises to transfer risks. Thirdly, in terms of legal supervision, electronic disk mainly relies on some self-defined laws and regulations, which will inevitably lead to regulatory loopholes or ineffective implementation of the system, which will bring losses to enterprises. However, the futures market is supervised by the State Council, China Securities Regulatory Commission, Exchange and other layers, and the system construction is relatively perfect, so enterprises do not have to worry about default and other issues. Finally, the more important difference between electronic disk and steel futures market is reflected in the system. Futures trading system mainly includes trading settlement system, risk control system and delivery system. The risk control system specifically includes margin system, price limit system and position limit system. Steel futures and electronic disk are similar in settlement system, and both adopt daily settlement system, and the profit and loss of customer accounts are settled after daily trading, but there are great differences in risk control and delivery. Risk control system margin system: According to the regulations of Shanghai Futures Exchange, the minimum trading margin of rebar and wire futures is 7% of the futures contract value, but the margin will be adjusted in different periods of contract listing and operation and when the contract positions reach different levels. Judging from the margin level of the futures market and the electronic market, the futures market is obviously much lower than the electronic market, which highlights the leverage of the futures market and makes investors occupy less funds, thus improving the efficiency of the use of funds. Moreover, adjusting the margin ratio with the changes of trading days and positions is more conducive to risk control and performance guarantee. The electronic disk is relatively simple in margin adjustment. Only when the agreed delivery month is entered will the margin ratio be adjusted to 40%, and the margin will not be adjusted at other times. Of course, this will be easier for investors, but it ignores the changes in market conditions and is not conducive to risk control. Price limit system: In addition to the 5% stipulated in the above contract, the Exchange will adjust the price limit range of rebar and wire futures when the market price fluctuates greatly (for example, the one-way change exceeds 7.5%, 9% and 10.5% for three consecutive days and five consecutive days) or when there are continuous extreme situations (for example, one-way daily limit or daily limit for several consecutive trading days). However, the regulation of electronic trading price limit is simple and simple, lacking adjustment. Although concise, it also ignores the market situation, which is not conducive to risk control and market liquidity. Position restriction system: there is no specific position restriction system in the electronic disk market, which is easy to manipulate the market and default because the position is too large to be delivered. However, the futures market has a detailed position restriction system, which clearly stipulates the positions of non-trading members, trading members and ordinary investors, thus avoiding the possibility of market manipulation and default, and ensuring the safety of trading and delivery. There are great differences between electronic delivery system and futures in delivery: First, at the level of delivery commodities, the delivery standard of rebar futures is higher and the specifications are diverse, which conforms to the development trend of China's industry and can meet the needs of different enterprises, while the delivery level of rebar in bulk electronic disk is lower and the specifications are single. The standard product of wire rod futures delivery is 8mm nominal diameter product, which is also in line with the national industrial development trend, because the country issued a new standard in September 2008 1. 8mm is the recommended nominal diameter, and 6.5mm is only a transitional product, so the exchange takes 6.5mm wire rod as a delivery substitute. On the contrary, 6.5mm is the delivery standard and 8mm is the delivery substitute, which is not conducive to the industrial adjustment of the country. Secondly, the delivery unit in the futures market is 300 tons and its integral multiple. This delivery unit is considered from the aspects of rational utilization of storage space, convenient railway transportation and giving full play to the function of futures market. Therefore, the delivery unit is large, which is not suitable for small vendors to carry out delivery operations. The delivery unit of electronic disk market is only 10 ton, which is very low and suitable for small traders. Thirdly, due to the imperfect system supervision in electronic disk delivery, the quality of delivered products cannot be guaranteed and the specifications are difficult to be unified. Moreover, due to reasonable delivery, serious problems such as overflow and shortage often occur, which brings great losses to related enterprises. In order to avoid the quality and short delivery of goods, Shanghai Futures Exchange has made strict regulations on the delivery of rebar and wire futures. For each delivery warehouse receipt, steel bars and wires must be produced by the same manufacturer, brand, registered trademark and nominal diameter. The rebar must also be a commodity with the same length (the rebar delivered in kind is 9m or12m), and the production date shall not exceed two consecutive days, with the earliest date being the production date of the warehouse receipt. Moreover, the delivery of rebar and wire rod in the futures market is based on the actual delivery, and the physical overflow of each warehouse receipt does not exceed 3%, and the long-short clause does not exceed 0.3%, thus avoiding the problem that the delivery party suffers serious losses due to excessive overflow in the delivery process. The Exchange has also made strict regulations on the validity period of delivery goods, that is, the validity period of delivery in the warehouse is within 90 days from the date of production, and warehouse receipts can only be made after entering the delivery warehouse within 30 days from the date of production, thus avoiding the losses caused to the consignee by the delivery of goods that are about to expire. Moreover, there are differences in the setting of delivery warehouses. The delivery of the electronic disk shall be conducted in the delivery warehouse designated by the electronic disk. Generally, due to the strong regionality of electronic disk, the designated delivery warehouse also has obvious regionality. The delivery warehouse in the futures market shall be determined by the exchange. At present, for the delivery of rebar and wire rod, the Exchange has designated delivery warehouses in North China and East China, and introduced a special factory warehouse delivery system as a supplement to the delivery warehouse of the Exchange, that is, qualified enterprises can apply for their own warehouses to become delivery warehouses, which is not only conducive to effectively solving the shelf life and transportation problems of products, but also conducive to the promotion of corporate brands. In addition, there are differences in delivery prices between the two markets. Generally, the average price of electronic disk five days before delivery is the delivery price, and the settlement price on the last trading day is the delivery price in the futures market. The two are also different in details such as distribution costs and distribution processes, which will not be repeated here. To sum up, we can clearly see the difference between steel futures and electronic trading in contract, transaction and delivery. The introduction of steel futures has a certain positive impact on the development of electronic disk market, and also helps to form a market system that organically combines steel spot and futures, standardize and improve the steel circulation market, and make China's steel market more standardized, healthy and orderly.