It is impossible to infer solely from an increase in the volume of transactions how the price of oil will change. The price will fall if the increase resulted from growth in supply, and it will rise if the increase resulted from growth in demand.
这是源自供需理论的一种平常却重要的观点。譬如，想想石油市场：仅仅从交易量的上升就推断石油的价格将会怎样变化，这是不可能的。如果这种上升源于供应量的增加，那么价格将下降。如果源于需求的增加，价格就会上升。