Norma, Norma, Arni Surwanti, and Alni Rahmawati. 2025. “The Analysis of Optimal Portfolio on Investment Decision Using Single Index Model on LQ45 Stocks (Listed on Indonesia Stock Exchange for The Period 2022-2024)”. Journal of Economics and Management Scienties 7 (4):670-77. https://doi.org/10.37034/jems.v7i4.204.