“…Among them, some models are derived by creating additional or variational objectives based on the MV model, e.g., skewness [4], volatility in the portfolios [5], mean absolute deviation [6], minimax [7], and value at risk [8,9]; some by incorporating additional constraints into the MV model, e.g., boundaries [10], cardinality [11], and transaction costs [12], or by relaxing existing constraints, such as weight from non-negativity to negativity [13]; and some by being extended before their suitability in a dynamic market, such as a prediction-based portfolio optimization model that can predict each stock's Mathematics 2021, 9, 2621 2 of 17 future return [14]. Since these portfolio optimization models are almost multi-objective and are very difficult to solve efficiently using mathematical programming and exact methods [15,16], further attention has been paid to the metaheuristic algorithms that have displayed high performance levels in solving multi-objective optimization problems in other fields. These algorithms include the niched Pareto genetic algorithm II (NPGA-II) [17], the strength Pareto evolutionary algorithm 2 (SPEA2) [18], the multi-objective evolutionary algorithm based on decomposition (MOEA/D) [19], particle swarm optimization (PSO) [20], an artificial bee colony (ABC) [21], a biased-randomized iterated local search algorithm [22], and so on.…”