At present, the London Metal Exchange (LME) is the largest bulk nonferrous metal futures exchange in the world, which has gone through 130 years. 1979 nickel has officially become one of the listed varieties in our institute. The exchange adopts the membership system (brokerage company system, in which the first and second members are market makers-members can directly become buyers or sellers of customers. Like other listed products, LME nickel futures are divided into electronic trading, telephone trading, over-the-counter trading, on-site single-product trading and on-site mixed (comprehensive) trading. Strictly speaking, an exchange can only be divided into on-site trading and off-site trading. The so-called electronic transactions and telephone transactions are off-site transactions (of course, when there are on-site transactions, customers conduct transactions by telephone), and comprehensive transactions are part of on-site transactions.

Electronic trading (domestic industry name), the exchange is called LME Select, that is, online electronic trading, which is the official electronic trading platform of the exchange. Class I and II members of the Exchange (brokerage companies) can directly enter the system to trade for customers. Customers can also buy and sell online directly through brokerage companies. The trading hours are from/kloc-0 am to 7 pm London time, and the trading hours partially overlap with the telephone trading hours and partially overlap with the on-site trading hours. At present, the trading volume of electronic disk is not large, but the trading price can basically represent the market price at that time.

Telephone transaction: Telephone transaction refers to the purchase and sale reached by customers through brokers and brokerage companies at any time on the working day of the exchange. At the same time, the telephone transactions between brokerage companies are also called telephone transactions. The telephone transaction time is any time of every working day, and the transaction price has close continuity with the electronic disk and on-site transaction price.

Over-the-counter transactions: LME over-the-counter transactions include electronic transactions and telephone transactions. That is, any transaction other than on-site trading is called off-site trading. Generally speaking, OTC trading is the most representative because of its long trading time.

Floor trading: also known as gesture trading, it is divided into floor trading of a single commodity-ringing, and floor trading of all commodities (that is, comprehensive trading)-kerb trading. Daily floor trading is divided into six trading periods (times), three in the morning and three in the afternoon. The trading time of each commodity is 5 minutes for the first two times in the morning, and the last time is mixed trading, with the time of 1.25 hours. For example, the early trading time of nickel is: the first time12:15-12: 20, and the second time 13:00- 13:05,13: 20. The trading time in the afternoon is basically the same as that in the morning, the first time is 15:25- 15:30 and the second time is16:10,16:.

The price of floor trading is basically only representative during the trading period. Once the trading time has passed, the price should basically refer to the over-the-counter trading price. Generally speaking, after the end of the on-site transaction, the off-site transaction basically continues the floor price, with little change. However, with the passage of time, the price may change significantly at any time.

If there is any correlation and mutual influence among floor price, comprehensive transaction price (floor mixed transaction price), electronic transaction price, telephone transaction price and over-the-counter transaction price, then they are interrelated and continuous in time sequence.