“…The hierarchical clustering algorithm is a methodology that robustly explores the clustering of a dataset to mine this information for connectedness visualization. It is worth nothing that GARCH-based models, entropy, and hierarchical clustering have successfully been applied to model volatility [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], to evaluate randomness in financial and economic data [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ], and to cluster financial data [ 36 , 37 , 38 , 39 , 40 , 41 ].…”