نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
The aim of this study is to analyze the structural characteristics of the optimal portfolio, with a specific focus on the role of firm size in asset allocation. To this end, we utilize the outcomes of a portfolio optimization model based on the Particle Swarm Optimization (PSO) metaheuristic algorithm. The model incorporates two key variables—firm size and systemic risk—and is applied to data from 25 selected companies listed on the Tehran Stock Exchange over the period 2011 to 2023. Companies were selected using a systematic elimination sampling method.
The findings reveal that the proposed portfolio structure is significantly influenced by firm size, with the model tending to allocate greater weight to larger and less risky firms. These results indicate that larger companies play a more stabilizing role in portfolio composition under conditions of market volatility and systemic risk. The presented analysis contributes to a deeper understanding of the performance of metaheuristic algorithms in financial decision-making and offers a foundation for improving asset allocation policies and portfolio design in emerging markets such as Iran.