Robust random fuzzy portfolio selection model with Arbitrage Pricing Theory using TS fuzzy reasoning method

This paper proposes a robust-based mean-variance portfolio selection problem with random fuzzy returns using a fuzzy reasoning method, particularly a standard TS fuzzy reasoning method. Arbitrage Pricing Theory (APT) is introduced as a future return of each security, and each factor in APT is assumed to be a random fuzzy variable whose mean is derived from a fuzzy reasoning method. Furthermore, under interval inputs of fuzzy reasoning method, a robust programming approach is introduced in order to minimize the worst case of the total variance. The proposed model is equivalently transformed into the deterministic nonlinear programming problem, and so the solution steps to obtain the exact optimal portfolio are developed.