Evaluation of the performance of companies included in the BIST sustainability index based on financial indicators and ESG score

Non-financial criteria are as guiding as the use of financial indicators in evaluating business performance. Financial ratios are the most preferred financial indicators. The non-financial measure is expressed as sustainability or ESG score. These universally determined criteria significantly influence investor choices. This study focuses on evaluating the financial and non-financial performance of businesses using multi-criteria decision-making techniques. The aim of the study is to monitor the performance of nine companies with uninterrupted financial data and ESG scores in the manufacturing sector in the BIST sustainability index for eight years between 2014 and 2021 and to rank the companies. LOPCOW, Standard Deviation, and Entropy methods were used to determine the criteria's importance weights before ranking the companies' performance. Arithmetic mean was used to combine the criteria's importance weights. The rankings among manufacturing businesses in the study were conducted using the WASPAS, TOPSIS, and COPRAS methods. The Borda method, an integration method, was used to combine the rankings determined for each year into a single ranking. The research revealed that the most important criterion for the manufacturing companies examined was the leverage ratio. The ESG criterion was found to be ranked second and third, alternating with the first two years. Among the manufacturing companies, EREGL ranked first. It can be considered normal that the leverage ratio is an important issue for companies in our country in terms of economic conditions. Sustainability reporting, which was previously voluntary for policy makers, became mandatory for publishing sustainability reports within the framework of determined scales at the beginning of 2024. Therefore, it is expected that the ESG score will come to the forefront in terms of criterion importance for future studies. Making ESG mandatory for listed companies, especially those included in the sustainability index, will be important in terms of the importance of ESG as a criterion. Among the companies examined in the research, it was found that five out of nine companies published in the sustainability index as of 2025 had published sustainability reports. Keywords: BIST Sustainability Index, Financial Performance, ESG, Multi-Criteria Decision Making Methods, Borda Method.