“…This reflects the time-varying nature of the linkages between volatilities. Diebold and Yilmaz (2012) analyze the existence of volatility spillovers 1 An important research topic in the literature is the analysis of international volatility spillovers (see for example, Dungey and Martin, 2007;Morana and Beltratti, 2008;Diebold and Yilmaz, 2009;Duncan and Kabundi, 2014;Ehrmann et al, 2011;Bayoumi and Bui, 2012;Antonakakis and Vergos, 2013;Apostolakisa and Papadopoulos, 2014;Beirne and Gieck, 2014;Awartania et al, 2013;Fernandez-Rodriguez et al, 2016;Yarovaya et al, 2016;Belke and Dubova, 2018). Despite the relevance of international spillovers, this paper only focuses on the volatility spillovers among US financial markets.…”