“…To better and properly forecast financial time series while adequately dealing with their respective nonlinear, nonstationary and noisy aspects, other workers used advanced and sophisticated intelligent systems such as gene expression programming (Karathanasopoulos, 2017), case‐based reasoning systems (Li et al ., 2013), ensemble and fusion intelligent systems (Albanis and Batchelor, 2007; Lahmiri, 2014a, 2018a; Sun, 2012), artificial neural networks (Aragonés et al ., 2007; Biscontri, 2012; Dunis et al ., 2013; Fadlalla and Amani, 2014; Haefke and Helmenstein, 2002; Vojinovic et al ., 2001), hybrid neuro‐fuzzy systems (Schott and Kalita, 2011; Trinkle, 2005), hybrid systems based on artificial neural networks and econometric models (Parot et al ., 2019), and deep learning (Galeshchuk and Mukherjee, 2017; Lahmiri and Bekiros, 2019).…”