Rafiana A. S., A.B., Maulana, M.I., Anwar, Burhanuddin and Nurman 2023. OPTIMAL PORTFOLIO FORMATION ANALYSIS USING THE SINGLE INDEX MODEL DURING THE COVID-19 PANDEMIC: A Study on The LQ 45 Index on the Indonesian Stock Exchange (IDX). JOURNAL OF HUMANITIES, SOCIAL SCIENCES AND BUSINESS. 2, 3 (Jun. 2023), 468–481. DOI:https://doi.org/10.55047/jhssb.v2i3.625.