This paper is the first attempt at testing the ‘time-varying’ and ‘time-scale dependent’ volatilities of and correlations between the selected Islamic stock indices of South East Asian countries and selected commodities for enhancing portfolio diversification benefits. Consistent with the results of our VECM, our analysis based on the application of the recent wavelet technique MODWT, indicates that the Singapore Islamic index is leading the other Islamic indices and the commodities. From the point of view of portfolio diversification benefits, based on the extent of dynamic correlations between variables, our results suggest that an investor should be aware that the Philippine Islamic stock index is less correlated with the crude oil in the short run (as evidenced in the continuous wavelet transform analysis) and that an investor holding the crude oil can gain by including the Malaysian Islamic stock index in the portfolio (as evidenced in the Dynamic conditional correlation analysis)

In this article, the MGARCH-DCC model is utilised to compare the usefulness of Bitcoin, gold, and crude oil as a hedge and safe haven for the US Islamic stock index. We utilised daily data from August 2014 to April 2022, which covers the most recent COVID-19 epidemic and the Russia-Ukraine conflict. We find the dynamic correlation between Bitcoin and the US Islamic stock index to be low and often negative during major economic and political events, showing that Bitcoin is a safe haven and hedging instrument, especially during the pandemic period. However, we find that Bitcoin is very volatile, limiting its use as a safe haven and hedging instrument compared to gold. Gold is more stable and negatively correlated with the US Islamic stock index, making it more appropriate as a diversifier and hedging instrument. Adding gold to the US Islamic stock index portfolio reduces the portfolio’s risk.

The aim of this article is to find diversification opportunities by examining the time-varying and time-scale-based volatility and correlation of the US and Chinese stock market indices with crude oil, gold and Bitcoin price returns, as well as the exchange rate of the Chinese Yuan Renminbi against the US Dollar (CNY/USD) using a vector error correction model (VECM), namely, maximum overlap discrete wavelet transformation (MODWT). Furthermore, individual and institutional investors may also reduce the risk of their investment portfolio by investing in commodities and stock markets from countries with a negative or substantially low correlation. Our VECM result shows that Bitcoin, crude oil and CNY/USD lead the other variables under consideration, indicating that changes in the prices of Bitcoin, crude oil and CNY/USD affect the US and Chinese stock market indices, as well as gold. Our research utilising the MODWT technique shows that Bitcoin leads crude oil at almost all levels, indicating that crude oil prices will respond to Bitcoin price movement in the long and medium term. However, investors may be deterred from using Bitcoin as a diversification tool due to its extreme volatility. The research also indicates that diversification with gold may help US investors. However, the continuous wavelet transformation finding shows that the diversification benefit effects will persist for a holding period of little more than 64 days. Our study results tend to emphasise the significance of using reasonably modern methods to identify diversification possibilities for investors with diverse investment horizons or holding stocks for various periods.