Optimizing ESG Leaders’ Stock Portfolio on the Indonesia Stock Exchange (IDX): A Single Index Model Analysis (2020-2023)Alviansyah Sofyan Saputra, Meylani Meylani, Nita Nurfauziah and Ardi GunardiE3S Web Conf., 593 (2024) 13001DOI: https://doi.org/10.1051/e3sconf/202459313001