A New Risk Measurement And Investment Model

This paper will give you a method for measuring risk . It uses the difference between the mean return rate and the return rate . It also depends on the probability of every special return rate. In this paper, I will try to prove some properties it should have as a method of measuring risk.In the real world, you must buy / sold stocks in integer in the stock market;there is a limit number of every security in the market;every investor has a definite capital which can be invested in the security market. So based on this conditions, I try to give you some method to solve this problem. After all, this paper does not consider the transaction cost, it's a limit of my research can be used in the real world .But it really has something much closer to the world .The method of solving this problem used are the new filled function method[4] and the enumerative method .At last a new investment theory is given .The code of this theory is that: only the probability of every return rate and the return rate can influence the price of the securities.