<![CDATA[This study aims to analyze and examine the effect of operational cost efficiency, financing decisions, and firm size on the financial performance of coal sub-sector companies listed on the Indonesia Stock Exchange (IDX) for the 2021–2025 period. This research employs a quantitative approach with an associative causal research design. Data collection utilized documentation methods through the companies' annual financial reports published by the IDX. The sample was selected using a purposive sampling technique, resulting in 26 companies with a total of 125 valid observation data points after data adjustment. Data analysis techniques include descriptive statistical analysis, classical assumption tests (normality test, multicollinearity test, heteroscedasticity test, and autocorrelation test), multiple linear regression analysis, and hypothesis testing comprising partial tests (t-test), simultaneous tests (F-test), and the coefficient of determination (R2) assisted by IBM SPSS Statistics software. The partial results indicate that operational cost efficiency has a negative and significant effect on financial performance. Financing decisions also have a negative and significant effect on financial performance. Meanwhile, firm size has a positive but insignificant effect on financial performance. Simultaneously, operational cost efficiency, financing decisions, and firm size have a significant effect on financial performance. The Adjusted R Square value of 0.436 indicates that 43.6% of the variation in financial performance is explained by these three independent variables, while the remaining 56.4% is influenced by other factors outside the research model.]]>
