... Numerous studies examine the relationship between commodity markets by applying various techniques such as conditional correlations (e.g., Shivered, 2019), multivariate GARCH (Cabrera and Schulz, 2016;Kang et al., 2017), vector autoregressive (e.g., Barbaglia et al., 2020), cointegration (Zhang and Wei, 2010;Ciaian, 2011;Wang and Wu, 2012;Manera et al., 2013;Al-Maadid et al., 2017;Shiferaw, 2019), wavelets (e.g., Tiwari et al., 2020;Kirikkaleli and Güngör, 2021), copula (Koirala et al., 2015;Mensi et al., 2017;Ji et al., 2018;Mokni, 2018;Ji et al., 2018Ji et al., , 2018Yuan et al., 2020;Albulescu et al., 2020;Kumar et al., 2020), variance decomposition spillover (e.g., Dahl et al., 2020;Bouri et al., 2021), and cointegration and Granger causality test (Nazlioglu and Soytas, 2011;Kaltalioglu and Soytas, 2011;Coronado et al., 2018;Vu et al., 2019;Fernandes and Araújo, 2020;Talbi et al., 2020;Mokni and Ben-Salha, 2020;Youssef and Mokni, 2021). They generally consider returns linkages and volatility linkages separately, 3 and disregard evidence of time-variation in the Granger causal relationships for a long sample period. ...