what do you mean by profitability Investment in securities is conducive to adjusting capital investment and improving the efficiency of capital use, thus guiding the rational flow of resources and realizing optimal allocation of resources. If these measures do not satisfy his base, Mr Trump still has the last option, which the Roman emperor and other dictators have long used in difficult times at home. That is to say, he can "swing the dog" by making external threats or launching foreign military adventures, thereby dispersing his supporters from what he and republican lawmakers have done. Under the theoretical framework of the theory, the theory of commodity market equilibrium and the monetary market equilibrium of Keynesian theory are unified. Marx's theory of interest rate decisions from the perspective of the source and essence of interest, taking into account the institutional factors in the role of interest rate decisions of interest theory, its theoretical core is the interest rate is determined by the average profit margin. Marx believed that under capitalism, interest is a part of profit and a form of conversion of surplus value.