Sitepu, Victor Bastanta, and Abdul Mukti Soma. 2025. “Comparison of Black Scholes and Garch Models Using Collar Strategy As a Hedging Efforts in the Telecommunication Industry (Telkomsel, XL, Indosat)”. Journal of Multidisciplinary Academic and Practice Studies 3 (3):651-75. https://doi.org/10.35912/jomaps.v3i3.3209.