In a certain period of time, the supply exceeds the demand, the inventory of shops and warehouses rises, and the goods are unsalable. With unsalable goods, in order to recover the cost, stores will choose to return goods and exchange them with suppliers. For consumers, they will choose price reduction promotion and activity package sales. In the next period of time, the price of unsalable goods will fall. When the supply exceeds demand and the replenishment speed of goods is too slow, stores will raise prices to slow down the circulation speed of goods. In addition, some speculators will raise the price of certain commodities in a certain period of time to reap huge profits.

Summary: Prices fluctuate with the fluctuation of supply and demand. Supply exceeds demand. The price has fallen. Supply exceeds demand and prices rise. It belongs to market regulation.