Research On The Relationship Between Stock Portfolio Investment And Risk Diversification

The stock market, as one of the world’s hottest investment market, attracting the attention of investors. Meanwhile, stock research has become the focus of investors as rational investment. The modern portfolio theory thinks that the reasonable investment portfolio of different kinds of risk assets can not only guarantee the profits but also reduce the risk of the portfolio. In this paper, I select Shanghai 50 and the Shenzhen Component Index of 20 rats in each (a total of 40) stock for the empirical analysis of the constituent stocks. This 40 stocks from 2005 to 2014 for the monthly return rate as the research object, on the basis of modern portfolio theory and Markowitz mean variance model to empirically analyze Chinese market portfolio size and revenue, risk diversification and dispersion degree. The empirical study finds that the change of stock portfolio is not the main way to guarantee or maintain portfolio returns; Portfolio expansion will be a combination of risk reduction, when the scale increases to a certain extent, the risk of changes tend to be stable; When the portfolio size reached 12, the risk of dispersion reaches 71.17%, in order to reduce both the cost of capital and the cost of management to protect the revenue and reduce the risk, the stock portfolio size had better be determined in 6 to 12 stocks...