Over the past two decades, a body of behavioral finance research has been devoted to exploring the behavioral patterns and trading performance of individual and institutional investor categories over time. time and through scholarships. In fact, this fascinating research topic is of considerable interest to both academics and market practitioners, as it has great academic value and practical implications for the industry. More specifically, capturing the trade structure and investment performance of each investor group in a particular country can shed light on some interesting questions such as market composition, information transmission, market formation, asset prices, as well as market efficiency and liquidity. As asymmetry is evident between institutional investors and individual investors (e.g., Alangar et al., 1999; Lin et al., 2007; Duong et al., 2009), each group is more likely to have its characteristics unique. In their 2008 study, Kaniel et al. point out that institutional investors are generally perceived as rational traders who are better informed and have a rather long-term investment perspective. In contrast, individual investors are generally considered to be unsophisticated traders, who prefer short-term investment horizons and are deeply involved in making investment decisions based on their feelings and grounded in their own cognitive biases. On the other hand, researchers working in the field of behavioral finance distinguish between two recognized trading models, based on investors' reactions to past stock price movements. The first pattern of behavior is called momentum investing or positive feedback trading, in which investors buy (sell) a stock in anticipation of a further rise (d...... middle of paper ......kes (2011) report significant evidence that all three types of investors – particularly insurers – are more contrarian when selling than buying, suggesting that investors are reluctant to realize losses, consistent with the evidence presented by Grinblatt and Keloharju (2001) and Odean (1998). More recently, Phansatan et al (2012) examined the Stock Exchange of Thailand (SET) and found that both individual and institutional investors appear to be traders. contrarian, unlike foreign investors who turn out to be positive feedback traders The number of institutions in the Thai stock market leads to a very lower security section, and therefore very poor overall trading performance. On the other hand, individual investors' trading behavior results in gains on the security section, but their poor market timing offsets these gains..