Because the price of imported copper fluctuates every day, if it is not a spot transaction, the price will change from the date of price negotiation to the date of actual delivery. The so-called premium, in layman's terms, is the extent of price increase or decrease before the actual delivery date. A premium is an increase, and a premium is a decrease.

For example, if the price on the negotiation date is 65,000 yuan/ton, and the price rises to 65,500 yuan/ton at the time of actual delivery, then the increased 500 yuan/ton is called premium. Conversely, if the actual delivery price is 64,500 yuan/ton, then the reduced 500 yuan/ton is called premium.