Analysis of Stock Price Movements of Conglomerate Groups Relative to The Jakarta Composite Index (JCI)

This study aims to analyze the relationship and influence of stock price changes within conglomerate groups on the movements of the Jakarta Composite Index (JCI) on the Indonesia Stock Exchange during the 2019–2025 period. A quantitative approach was employed, utilizing secondary data consisting of daily stock price changes and the JCI. The sample was selected using a purposive sampling technique, with the current and former constituents of the Kompas100 Index serving as the screening universe, from which stocks affiliated with conglomerate groups were identified. Based on the research criteria, 18 conglomerate groups comprising 57 companies were selected. The daily stock returns for each company were aggregated by conglomerate group and used as independent variables, while the daily return of the JCI served as the dependent variable. The analysis was conducted using multiple linear regression with the assistance of EViews 13. The results indicate that for all annual models throughout the 2019–2025 period, the Prob. (F-statistic) was 0.000, demonstrating that the conglomerate group stock variables are, when taken together, statistically significant in their relationship to changes in the JCI. The Adjusted R² values ​​for each year are 67.30% in 2019, 90.81% in 2020, 76.28% in 2021, 67.33% in 2022, 65.28% in 2023, 76.20% in 2024, and 81.89% in 2025. A pooled regression for the 2019–2025 period yields an R² of 76.30% and an Adjusted R² of 76.10%. These results indicate a relatively high explanatory power for the model.