International Journal of Quantitative Research and Modeling
Vol. 7 No. 2 (2026): International Journal of Quantitative Research and Modeling (IJQRM)

Efficient Frontier Analysis of Islamic and Conventional Bank Stock Portfolios: Evidence from Four IDX-Listed Issuers Using the Markowitz Model

Dede Irman (Communication in Research and Publications, Bandung, Indonesia)
Alim Jaizul Wahid (Master'
s Program of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jatinangor, West Java, Indonesia)



Article Info

Publish Date
03 Jul 2026

Abstract

This study investigates and compares the portfolio performance of Islamic and conventional bank stocks listed on the Indonesia Stock Exchange (IDX) using the Markowitz Mean-Variance optimization model. Four issuers were selected: PT Bank Rakyat Indonesia Tbk (BBRI), PT Bank Mandiri Tbk (BMRI), PT Bank Rakyat Indonesia Syariah Tbk (BRIS), and PT Bank Pembangunan Daerah Banten Tbk (BPAA), representing two conventional and two Islamic banking stocks respectively. Daily closing price data spanning from January 2021 to December 2023 (756 trading days) were employed to compute expected returns, variance, covariance, and correlation coefficients. Two optimal portfolios were constructed for each category: the Minimum-Variance Portfolio (MVP) and the Maximum-Sharpe Portfolio (MSP). Performance evaluation was carried out through multiple metrics including the Sharpe Ratio, Treynor Ratio, Jensen's Alpha, and Sortino Ratio. Results indicate that Islamic bank portfolios consistently outperform conventional bank portfolios on a risk-adjusted basis. The Maximum-Sharpe Islamic portfolio achieved a Sharpe Ratio of 1.765 compared to 1.342 for its conventional counterpart. These findings suggest that Islamic banking stocks, with their inherently lower leverage and prohibition on speculative instruments, exhibit more favourable risk-return characteristics, providing actionable insights for investors seeking Shariah-compliant investment alternatives.

Copyrights © 2026






Journal Info

Abbrev

ijqrm

Publisher

Subject

Computer Science & IT Decision Sciences, Operations Research & Management Engineering Environmental Science Physics

Description

International Journal of Quantitative Research and Modeling (IJQRM) is published 4 times a year and is the flagship journal of the Research Collaboration Community (RCC). It is the aim of IJQRM to present papers which cover the theory, practice, history or methodology of Quatitative Research (QR) ...