Rikumahu, Brady, and Mu’arif Fandhi Akhmad. 2025. “Comparison of Black-Scholes Models Using Historical Volatility and Garch Volatility in Collar Strategy As Hedging Efforts for Towr and Tbig Stocks”. International Journal of Accounting and Management Information Systems 1 (2):143-61. https://doi.org/10.35912/ijamis.v1i2.3043.