PurposeThe purpose of the study is to adopt Morlet’s wavelet method to examine the differences in the level of volatility (i.e. riskiness) between the conventional and Shari’ah indexes during the COVID-19 pandemic (February 4 to June 19, 2020) on selected Association of South East Asian Nation (ASEAN) and Gulf Cooperation Council (GCC) countries. As a comparison, the equivalent time period of relative tranquillity is used; February 4 to June 19, 2019.Design/methodology/approachMorlet’s wavelet method is used in analyzing the volatility levels for both the conventional and Shari’ah indexes before and during the COVID-19 pandemic for the selected ASEAN and GCC countries.FindingsThis study has several findings; first, the markets in the ASEAN region appear to be more volatile during the pandemic than in the GCC region. Second, most of the Shari’ah indexes were more volatile during the COVID-19 pandemic than their conventional counterparts. Nevertheless, the GCC index pairs appear to show more similarities between both the Shari’ah and conventional index.Practical implicationsThe findings from this study indicate that investors, government, regulators and all other stakeholders should stay vigilant during a pandemic or health threat period as it has become a pertinent source of volatility spillovers. As such, investors should devise optimal asset allocation strategies, portfolio diversification and portfolio rebalancing measures, taking into consideration not only financial adversity but also public health gravity as a potential source of turbulent markets.Originality/valueThis study uses the wavelet method to examine the volatility level of both the Shari’ah and conventional indexes during the COVID-19 pandemic and its equivalent time frame in 2019. It has further added to the Islamic literature by comparing the volatility between selected ASEAN and GCC countries. The wavelet method is most appropriate for short-duration studies as it captures both the time and frequency domains of the time-series behavior.