This study examines how controlling ownership, exchange rate volatility, and firm profitability (ROA) influence stock volatility in Indonesia, with market- wide volatility acting as a moderating factor. Using ownership data from the Bloomberg Terminal, the analysis captures ultimate controlling shareholders and cross-ownership structures among 37 permanent constituents of the Kompas 100 Index over the 2014–2024 period, yielding 370 firm-year observations from Indonesia’s most liquid and institutionally monitored firms. Panel data estimation using Fixed Effects and Random Effects models addresses unobserved firm heterogeneity and time-specific influences, while a COVID-19 and post-COVID dummy variable is incorporated to account for structural breaks during periods of systemic stress. The results indicate that controlling ownership consistently reduces stock volatility, even after controlling for pandemic-related disruptions, suggesting that concentrated control strengthens monitoring and stabilizes investor expectations during both normal and crisis periods. Exchange rate volatility significantly increases stock volatility, confirming its role as a key macro-financial transmission channel in Indonesia’s externally exposed economy, while higher ROA exerts a stabilizing effect under normal market conditions. The moderating analysis further shows that elevated market volatility weakens the stabilizing influence of controlling ownership and profitability, while amplifying the impact of exchange rate fluctuations, highlighting how systemic shocks can dominate firm-level fundamentals. Overall, this study integrates governance structure, macroeconomic risk, market-wide volatility, and structural breaks into a unified empirical framework, offering insights relevant for investors, regulators, and corporate governance policy in emerging markets.