“…Another favorable property for a portfolio is sparsity, which helps to minimize trading costs. Consequently, sparse mean‐reverting portfolios have been studied (Brodie et al., 2009; d'Aspremont, 2011; Fogarasi and Levendovszky, 2012, 2013; Sipos and Levendovszky, 2013; Sipos and Levendovszky, 2015; Cesarone et al., 2018; Long et al., 2018; Corsaro and De Simone, 2019; Zhang et al., 2020; Brito and Júdice, 2021; Naccarato et al., 2021; Sehgal and Mehra, 2021; van Staden et al., 2021). Sparsity has also shown to be advantageous in numerous applications (Shen and Mousavi, 2018; Mousavi et al., 2020, 2019; Mousavi and Shen, 2019; Shen and Mousavi, 2019; Mohammadi et al., 2020, 2021a, 2021b).…”