This study examines the impact of stock liquidity on stock price crash risk and the moderating role of institutional blockholders in Vietnam's stock market. Using firm-level data from 2010 to 2020, the authors find that stock price crash risk increases with stock liquidity, particularly in firms owned by institutional blockholders, especially foreign ones. The relationship is more pronounced when institutional blockholders engage in intensive selling in the future. The findings suggest that high liquidity encourages institutional blockholders to trade, and their aggressive selling upon receiving private bad news can lead to stock price crashes. The study provides practical implications for managers and investors, emphasizing the importance of timely information disclosure and considering the risks associated with liquidity and blockholder trading. The research contributes to the literature by showing that blockholder activities can explain the positive relationship between liquidity and crash risk.This study examines the impact of stock liquidity on stock price crash risk and the moderating role of institutional blockholders in Vietnam's stock market. Using firm-level data from 2010 to 2020, the authors find that stock price crash risk increases with stock liquidity, particularly in firms owned by institutional blockholders, especially foreign ones. The relationship is more pronounced when institutional blockholders engage in intensive selling in the future. The findings suggest that high liquidity encourages institutional blockholders to trade, and their aggressive selling upon receiving private bad news can lead to stock price crashes. The study provides practical implications for managers and investors, emphasizing the importance of timely information disclosure and considering the risks associated with liquidity and blockholder trading. The research contributes to the literature by showing that blockholder activities can explain the positive relationship between liquidity and crash risk.