Lu Lei, a deputy governor of the People's Bank of China, wrote in a preface to the publication Monetary Theory that the pressing problem facing major advanced economies is to "save the central bank from the central bankers." Although this line of thinking is by no means the current central bank digital currency (CBDC), because I don't think CBDC has changed the institutional meaning of currency increment, is there a digital currency that can not only overcome the impact of various digital assets, but also achieve the effect of stablecoins, and maintain the existence of sovereign currencies (solving the problem of monetary unification but fiscal dispersion in the euro)? At present, digital assets are following the old path of the gold standard, and the idea of stablecoins is nothing more than a realistic formulation of the "soft version" of the optimal currency area theory. In the forecasting and practice of monetary economics, there are two people who deserve great respect - the recently deceased Robert Mundell and the hitherto unknown Satoshi Nakamoto, who has watched his creation of bitcoin evolve into an extremely expensive digital asset, currently consuming enough energy for hundreds of millions of people around the world to mine the last 2 million coins each year. According to the marginal cost pricing method, the closer a bitcoin is to an asset, the farther it is from a widely circulated currency.