“…The study of heuristics for the index tracking problem is an open problem because the cardinality constraint, intrinsic for index tracking models, makes it difficult to compute optimal solutions in practical time by an exact solver. Nature-inspired algorithms have been widely adopted for portfolio optimization models, especially for the construction of tracking portfolios (Ruiz-Torrubiano and Suarez, 2009;Wang et al, 2012;Scozzari et al, 2013;Sant'Anna et al, 2017b;Kalayci et al, 2019;Strub and Trautmann, 2019;de Amorim et al, 2021). Baykasoglu et al (2015) provided evidence on the potential that greedy randomized adaptive search procedure (GRASP) has against standard portfolio optimization algorithms, including nature-inspired, to solve instances of a problem containing the aforementioned cardinality constraint, named cardinality-constrained meanvariance optimization problem.…”