What do you mean good money drives out bad money?
This is the process of good money driving out bad money. When all kinds of unrealized paper money are circulating in the market, the currency with stable value, that is, the so-called "good currency", is the currency with unstable or devalued value, that is, the so-called "bad currency", because people are willing to hold the currency with stable value and are expelled from the circulation field. In countries with a fixed exchange rate system, if their currencies are overvalued, the black market will inevitably "speculate" on foreign exchange, and foreign currencies with higher actual purchasing power will replace those with lower actual purchasing power.
Good money drives out bad money.
Good money drives out bad money, which is a completely opposite law to Gresham's law, that is, when two currencies with different actual values but nominally the same value circulate at the same time, the currency with higher actual value, that is, good money, will flood the market. And the currency with lower real value, that is, bad money, will definitely withdraw from commodity circulation. When all kinds of unrealized paper money are circulating in the market, the currency with stable value, that is, the so-called "good currency", is the currency with unstable or devalued value, that is, the so-called "bad currency", because people are willing to hold the currency with stable value and are expelled from the circulation field.