Nawosah, VivekAlajmi, Mona2024-02-012024-02-012023-12-04https://hdl.handle.net/20.500.14154/71348This study examines the effects of the subprime crises and COVID-19 on stock market volatility in the United States, utilizing the GJR GARCH model. The data utilized is the daily closing prices of the S&P 500 stock index. The study's findings highlight the prevalence of volatility clustering during the subprime crisis that occurred between 2007 and 2008. However, the lack of a substantial asymmetric evidence suggests an absence of compelling empirical proof for the existence of asymmetry within that period and during the COVID-19 pandemic, it was observed that there were occurrences of volatility clustering and asymmetry. This shows that compared to positive shocks, negative shocks have a more significant effect on increasing volatility which is commonly known as leverage effects.35enCOVID-19GJR GARCH modelvolatilityS&P 500subprimeThesis