The median price is indeed the average of the spot buying price and selling price, but the spot buying price and selling price are not the exchange rates quoted by the Bank of China, but the central bank's pricing is equivalent to the reference price of a commodity. The actual price will fluctuate around here according to the relationship between supply and demand, but the fluctuation range will not be too large, but this is an exception. This shows that from the perspective of commercial banks, the demand for RMB from US dollars has increased, so the buying price has increased, even exceeding the median price set by the central bank.

This question is easily confused. I have calculated whether the middle price is the buying price plus selling price divided by two on the foreign exchange quotation, and found that it is not. Later, after checking the information, I learned that the central bank's median price is the standard price of the central bank, and the buying price and selling price of commercial banks are different.