“…Arguably the most contentious issue about faith-based investments vehicle is whether ethical overlays have a bearing on financial performance. Whilst a number of previous studies have considered this area ( Hammoudeh et al, 2014 , Al-Khazali et al, 2014 , Fu et al, 2020 , Abu-Alkheil et al, 2020 , Umar et al, 2020 , Climent et al, 2020 , Haddad et al, 2020 , Rehman et al, 2020 , Anjum, 2020 , Widyanata and Bashir, 2020 , Sherif, 2016 ), much uncertainty remains regarding the significant differences between conventional and faith-based investments. The general perception and critique facing ethical investments stem from their contradiction with the principles of the efficient portfolio theory of Markowitz 1952, cited in Dhrymes (2017) .…”