Akademik Veri Yönetim Sistemi
BORSA ISTANBUL REVIEW, cilt.26, sa.2, ss.1-59, 2026 (SSCI, Scopus)
A vital tool for addressing the difficulties in defining an element’s membership in a set when there is uncertainty about multiple discrete values in decision-making is the Hesitant Fuzzy Set, an extension of fuzzy sets. A Fermatean hesitant fuzzy set is offered to guarantee that the parameters experts apply to evaluate an alternative regarding the likelihood of membership and non-membership are relevant in this study. Problems with portfolio selection are ideally suited for multi-attribute decision-making algorithms. Within the multi-attribute decision-making paradigm, complicated subjective preferences and diversified financial indices influence investment decisions. Aggregate operators of new sets are defined to implement decision-making issues for multi-attributed groups. We looked into the main properties of the interval-valued Fermatean hesitant fuzzy sets. We compare two interval-valued variables with a new accuracy function and score function. The application of the algorithm based on an interval-valued Fermatean hesitant fuzzy set was selected for the investment portfolio selection problem. Companies in the S&P 500 were analyzed, and criteria for selecting investment portfolios were established. To be used, this data was trans- formed into interval-valued Fermatean fuzzy components. Calculations were performed to demonstrate the suitability of the suggested approach. The suggested novel approach was contrasted with earlier approaches. The suggested method’s superiority and consequences were stated per the results. The study’s limitations are listed.