Diversification of securities, the establishment of a scientific and effective portfolio of securities; It eventually admitted that the app had broken down, but that it had been selling at 17 pounds at the station. However, when I got the reply, I had already paid the extra fee before the early discount ended. Lay the foundation In the early 20th century, famous American economist elvin fisher developed the theory of economic gain. In its book "the nature of capital and yield", first, the concept of yield is analyzed in terms of the performance of earnings, and three different types of benefits are proposed: The five-year average interest rate is also gradually rising, now more than 2 percentage points for the first time since July 2016. The market is the economic contact method which is the basic content of Commodity Exchange. Under the condition of commodity economy, the premise of exchange generation and existence is social division of labor and commodity production. Because of the social division of labor, the different producers, respectively, engaged in the production of different products, did not meet the needs of themselves and others and exchange their respective product, so that the general labor products into commodities, make the product production is transformed into commodity production. It is under this condition that the market for goods to be exchanged to meet the needs of different producers is born. Therefore, the market is the product of the division of labor and the exchange of goods under the conditions of commodity economy. The market and commodity economy have inalienable internal relation.