But in order to better future, we must expand the definition of the word "profit", the economic benefits and social benefits are included, and understand that block chain itself is a social innovation of technical solutions. Turning interest into creating equality - bubbles are a sign of market demand and represent a majority of people's expectations of financial returns. We should see it as an opportunity for development. But if we stop, we may continue to centralize wealth, repeat the traditional power structure and miss out on real opportunities. In his theory, money supply is controlled by the central bank and is an exogenous variable with no interest rate elasticity. At this point, monetary demand depends on people's psychological "liquidity preference".