This study examines the impact of two major financial crises— the 2008 global financial crisis and the 2019–2021 global pandemic—on stock market volatility in developed and emerging markets. Using GARCH models, the research finds that emerging markets responded similarly to both crises, while developed markets showed different reactions, being more volatile during the pandemic than the 2008 crisis. Economic strength does not always protect markets from economic turmoil, as both developed and emerging markets experienced significant volatility. The study also reveals asymmetric volatility, where negative news has a greater impact on stock market volatility than positive news. The findings suggest that investors should consider diversifying across developed and emerging markets during crises. Portfolio managers can use these insights to better understand market behavior and advise investors. The study highlights the importance of considering market integration and the role of economic factors in shaping market responses to crises. The research contributes to the understanding of financial market dynamics and provides implications for investment strategies and policy-making.This study examines the impact of two major financial crises— the 2008 global financial crisis and the 2019–2021 global pandemic—on stock market volatility in developed and emerging markets. Using GARCH models, the research finds that emerging markets responded similarly to both crises, while developed markets showed different reactions, being more volatile during the pandemic than the 2008 crisis. Economic strength does not always protect markets from economic turmoil, as both developed and emerging markets experienced significant volatility. The study also reveals asymmetric volatility, where negative news has a greater impact on stock market volatility than positive news. The findings suggest that investors should consider diversifying across developed and emerging markets during crises. Portfolio managers can use these insights to better understand market behavior and advise investors. The study highlights the importance of considering market integration and the role of economic factors in shaping market responses to crises. The research contributes to the understanding of financial market dynamics and provides implications for investment strategies and policy-making.