The Studying On Fuzzy Portfolio Selection Models Based On Credibilitic Theories

How to balance the return and risk of portfolio attracts many scholars and investors' attention all the time.It's a key point of research to reduce the risk of the portfolio and obtain certain profit.In order to make the right investment decisions,identification and quantify of risk and the appropriate risk quantitative indicators are important.This thesis deals with investment portfolio decisions in fuzzy environment due to vagueness and uncertainty in financial market which affect investment decisions.Variance,absolute deviation and entropy are used to measure risk.Further,considering capital budget constraints and investment proportion limitations,three fuzzy portfolio optimization models are established aiming minimizing risk based on credibilitic theories.Then an improved pivoting algorithm is designed to obtain the optimal portfolio strategy.Finally,an example is given to illustrate the effectiveness of the proposed models.It shows that the return and risk of portfolio is basically positive.In finally,there's certain comparability of three portfolio optimization models because they are all based credibilitic theories from two different ways.It is proved that the optimization models are effective,and there is some reference of the optimal investment strategies to investors.