Unlike existing literature that emphasizes the role of foreign institutional participation in improving transparency and governance, this study introduces a distinct mechanism centered on the "exit threat" posed by foreign investors. Using a difference-in-differences research design, we show that firms subject to liberalization significantly reduce related-party transactions and achieve higher market valuations. Our findings suggest that foreign institutional investors enhance governance through their implicit threat of exit, particularly in firms with higher stock market liquidity, greater blockholder presence and shareholding, and stronger managerial wealth-performance sensitivity. Additionally, the positive effect of market liberalization on curbing tunneling is observed exclusively in financing-related transactions, with no significant impact on goods-and-services-related transactions. Finally, we demonstrate that controlling shareholders’ expropriation increases during periods of stock market de-globalization, highlighting the critical role of financial openness in protecting minority shareholders.