Historically, almost all major bubbles have been fueled not by real gold and silver, but by credit.

Credit can be created easily: we borrow money to buy stocks and houses, and prices rise; the higher they rise, the more people borrow money to rush in, forming a self-reinforcing cycle. The result is that the total amount of financial wealth far exceeds the actual currency in society. A frightening fact is that currently, for every 8.5 yuan of book assets in the financial market, there is only 1 yuan of real liquidity supporting it.