“…Therefore, it is almost impossible to determine random distributions of future returns. As a nonprobabilistic approach, many researchers proposed fuzzy-based portfolio selection problems using the fuzzy theory (Bilbao-Terol et al [7], Carlsson et al [8], Duan and Stahlecker [9], Huang [10,11], Inuiguchi and Tanino [12], Tanaka et al [13,14], and Watada [15]). Furthermore, some researchers proposed portfolio models with both randomness and fuzziness, for instance, fuzzy random portfolio selection problems (Katagiri et al [16]) and random fuzzy portfolio selection problems (Hasuike et al [17], Huang [18]).…”