This paper examines whether foreign investor heterogeneity plays a role in stock liquidity on a sample of 27,976 firms from 39 countries.Results show that foreign direct ownership is negatively,while foreign portfolio ownership is positively,associated with various measures of stock liquidity.During the 2008 market downturn,liquidity falls more sharply for firms with larger foreign direct investment than foreign portfolio investment.Consistent with theoretical predictions,our results also indicate that foreign investors influence stock liquidity through both trading activity and information channels.The evidence suggests that the value-enhancing benefits from foreign direct investors’ monitoring efforts outweigh the liquidity costs and high adverse selection premium demanded by less informed investors.In contrast,however,the positive impact of foreign portfolio ownership on firm performance,as documented in existing literature,becomes negative and is not robustly significant after controlling for liquidity.