This paper examines whether domestic investors outperform foreign investors by using transaction data from Stock Exchange of Thailand during 1999 to 2004. We find that foreign investors, in general, trade at worse price than domestic investors who have more information advantage. However, foreign investors perform best when buying mid-cap and large size stocks during the bull market which may be due to more experience and better access to research.Individual investors tend to follow contrarian trading strategy which leads them to act as the liquidity provider to institutions. The intense of trade imbalance can predict future returns. The intense of individuals selling occurring at peak price influences future negative return. The intense buying of foreign and institutional investors is followed by price increases.