Zain, Z.A., Mussafi, N.S.M. and Supandi, E.D. 2025. CLUSTER ANALYSIS OF K-MEANS AND WARD METHOD IN FORMING A ROBUST PORTFOLIO: AN EMPIRICAL STUDY OF JAKARTA ISLAMIC INDEX. BAREKENG: Jurnal Ilmu Matematika dan Terapan. 19, 1 (Jan. 2025), 537-546. DOI:https://doi.org/10.30598/barekengvol19iss1pp537-546.