The Over-Reaction Effect in the Stock Exchange of Thailand: An Empirical Study


Nitis Pokavattana Thananporn Sethjinda Nopphon Tangjitprom


     One of the main cornerstones of traditional financial theory is the Efficient Market Hypothesis (EMH). However, several violations of EMH have been discovered to the contrary of explanation provided by traditional financial theory. One of the key discoveries was the over-reaction effect of investors to recent information over base-rate data by De Bondt and Thaler (1985), which has been further studied in many different markets. Inspired by the work of De Bondt and Thaler (1985), this study investigated the over-reaction effect in the Stock Exchange of Thailand during 2012–2017 and the total return to investors based on the contrarian trading strategy by tracking performance of past losers and winners portfolio. In terms of method of analysis, this study tracked the total return index of stocks listed in the Stock Exchange of Thailand tracked during 2012–2014 to identify top 20% winners and bottom 20% losers. Equal weighted portfolios of winners and loser portfolios were formed with Cumulative Average Returns (CARs) tracked during 2015-2017 for comparison of performance. Mean difference and t-test were performed to test statistical significance. The results show that loser portfolios outperformed winner portfolios by 35.48%, 31.77%, and 55.87% at 1 year, 2 years, and 3 years after ranking, respectively. The differences between the returns generated by loser and winner portfolio were statistically significant from the 27th month onward. This study provides supporting evidence for the over-reaction effect in the Stock Exchange of Thailand during the study period. Results of portfolio tracking suggest that over-reaction of investors in the Stock Exchange of Thailand may present an opportunity for “contrarian trading strategies” over a medium term holding period. In other words, contrarian investors could benefit from tracking performance of underpriced stocks, for which the market has underestimated earning potential and business prospects and avoiding position in overpriced “hot” stocks, for which the market has overreacted to positive news, resulting in overpricing.

Keywords: Behavioral Finance, Over-Reaction Effect, Contrarian Trading Strategies, Efficient Market Hypothesis (EMH)     


Ali, N., Nassir, A. M., Hassan, T., & Abidin, S. Z. (2010). Short Run Stock Over-Reaction: Evidence from Bursa Malaysia. International Journal of Economics and Management, 4(2), 319-333. Retrieved from http://

Ali, R., Ahmad, Z., & Anusakumar, S. V. (2011). Stock Market Over-Reaction and Trading Volume: Evidence from Malaysia. Asian Academy of Management Journal of Accounting & Finance, 7(2), 103-119. Retrieved from

Archana.S, Safeer, M., & Kevin, S. (2014). A Study on Market Anomalies in Indian Stock Market. International Journal of Business and Administration Research Review, I(3), 128-137. Retrieved from

Arrow, K. J., & Debreu, G. (1954). Existence of an Equilibrium for a Competitive Economy. Econometrica, 22(3), 265-290. DOI: 10.2307/1907353 Retrieved from

Barberis, N., Shleifer, A., & Vishny, R. (1998). A Model of Investor Sentiment 1. Journal of Financial Economics, 49, 307-343. Retrieved from

Chan, K. C., Gup, B. E., & Pan, M-S. (1997). International Stock Market Efficiency and Integration: A Study of Eighteen Nations. Journal of Business Finance & Accounting, 24(6), 803-813.

Chiao, C., & Hueng, C. J. (2005). Over-reaction Effects Independent of Risk and Characteristics: Evidence from the Japanese Stock Market. Japan and the World Economy, 17(4), 431-455. DOI: 10.1016/j.japwor.

Clarke, J., Jandik, T., & Mandelker, G. (2001). The Efficient Markets Hypothesis. Expert Financial Planning: Advice from Industry Leaders, 126-141. Retrieved from

Daniel, K., Hirshleifer, D., & Subrahmanyam, A. (1998). Investor Psychology and Security Market under and Over-reactions. The Journal of Finance, 53(6), 1839-1885.

De Bondt, W. F. M., & Thaler, R. (1985). Does the Stock Market Overreact? The Journal of Finance, 40(3), 793-805. DOI: DOI: 10.1111/j.1540-6261.1985.tb05004.x

DeBondt, W., Forbes, W., Hamalainen, P., & Muradoglu, Y. G. (2010). What can Behavioural Finance Teach us about Finance? Qualitative Research in Financial Markets, 2(1), 29-36.

Degutis, A., & Novickytė, L. (2014). The Efficient Market Hypothesis: A Critical Review of Literature and Methodology. Ekonomika, 93(2), 7-23.

Dimson, E., & Mussavian, M. (1998). A Brief History of Market Efficiency. European Financial Management, 4(1), 91-103. DOI: 10.1111/1468-036X.00056

Fung, A. K-W., & Lam, K. (2004). Over-Reaction of Index Futures in Hong Kong. Journal of Empirical Finance, 11(3), 331-351.

Glaser, M., Nöth, M., & Weber, M. (2004). Behavioral Finance. In D. J. Koehler, & N. Harvey (Eds.), Blackwell Handbook of Judgment and Decision Making-Chapter 26 (pp. 527-546). Oxford: Blackwell Publishers.
Groenewold, N., & Kang, K. C. (1993). The Semi-Strong Efficiency of the Australian Share Market. Economic Record, 69(207), 405-410. DOI: 10.1111/j.1475-4932.1993.tb02121.x

Huang, H-H., Chan, M-L., Huang, I-H., & Chang, C-H. (2011). Stock Price Volatility and Over-Reaction in a Political Crisis: The Effects of Corporate Governance and Performance. Pacific-Basin Finance Journal, 19(1), 1-20.

Huang, J. Y., Shieh, J. C. P., & Kao, Y-C. (2016). Starting Points for a New Researcher in Behavioral Finance. International Journal of Managerial Finance, 12(1), 92-103. DOI: 10.1108/IJMF-05-2015-0111

Kaestner, M. (2006). Investors’ Misreaction to Unexpected Earnings: Evidence of Simultaneous Over-Reaction and Underreaction. ICFAI Journal of Behavioral Finance, 3(1), 1-17. Retrieved from

Kapoor, S., & Prosad, J. M. (2017). Behavioural Finance: A Review. Procedia Computer Science, 122,

Kim, J. H., & Shamsuddin, A. (2008). Are Asian Stock Markets Efficient? Evidence from New Multiple Variance Ratio Tests. Journal of Empirical Finance, 15(3), 518-532.

Kulwanich, J. (2013). Herding Behaviors in the Stock Exchange of Thailand. Kasetsart Journal of Social Sciences, 34, 43-59.

Lerskullawat, P., & Ungphakorn, T. (2018). Does Over-Reaction still Exist in Thailand? Kasetsart Journal of Social Sciences.

Lin, A. Y., & Swanson, P. E. (2010). Contrarian Strategies and Investor Overreaction under Price Limits. Journal of Economics Finance, 34, 430-454. DOI: 10.1007/s12197-009-9075-5

Maheshwari, S., & Dhankar, R. S. (2014). A Critique of Over-Reaction Effect in the Global Stock Markets Over the Past Three Decades. IOSR Journal of Business and Management, 16(4), 25-32. Retrieved from

Malkiel, B. G., & Fama, E. F. (1970). Efficient Capital Markets: A Review of Theory and Empirical Work. The Journal of Finance, 25(2), 383-417. DOI: 10.1111/j.1540-6261.1970.tb00518.x

Markowitz, H. (1952). Portfolio Selection. The Journal of Finance, 7(1), 77-91. DOI: 10.1111/j.1540-6261.1952.tb01525.x

Merton, R. C. (1969). Lifetime Portfolio Selection under Uncertainty: The Continuous-Time Case. The Review of Economics and Statistics, 51(3), 247-257. DOI: 10.2307/1926560 Retrieved from ttps://www.

Mylonakis, J. (2012). An Investigation of the Efficiency of Portfolio Investors’ Behavior. International Journal of Business and Social Science, 3(6), 13-24. Retrieved from

Neill, H. B. (2007). The Art of Contrary Thinking. Idaho, USA: Caxton Press.

Panyakosa, T. (2004). Assessment of Over-Reaction Behavior of Common Stock Price Fluctuation in the Stock Exchange of Thailand. (Unpublished master’s independent study), Chiang Mai University, Chiang Mai.

Poshakwale, S. (1996). Evidence on Weak form Efficiency and Day of the Week Effect in the Indian Stock Market. Finance India, 10(3), 605-616.

Qiao, Z., Chiang, T. C., & Tan, L. (2014). Empirical Investigation of the Causal Relationships Among Herding, Stock Market Returns, Illiquidity: Evidence from Major Asian Markets. Review of Pacific Basin Financial Markets and Policies, 17(3), 1450018. DOI: 10.1142/S0219091514500180

Rattanasri, W., & Vichitthamaros, P. (2018). The Study of Herding Behavior in the Stock Exchange of Thailand during 2010–2015. WMS Journal of Management, 7(1), 9-20.

Ritter, J. R. (2003). Behavioral Finance. Pacific-Basin Finance Journal, 11(4), 429-437.

Ruttanajongkol, S. (2010). Contrarian Profits in the Stock Exchange of Thailand. (Unpublished master’s independent study), Kasetsart University, Bangkok.

Saisingthong, K. (2003). A Study of Over-Reaction of Stock Return in the Stock Exchange of Thailand. (Unpublished master’s thesis). Kasetsart University, Bangkok.

Statman, M. (2014). Behavioral Finance: Finance with Normal People. Borsa Istanbul Review, 14(2), 65-73.

Tripathi, V., & Gupta, S. (2009). Over-Reaction Effect in Indian Stock Market. Asian Journal of Business and Accounting, 1-2, 93-114. Retrieved from

Von Neumann, J., & Morgenstern, O. (1944). Theory of Games and Economic Behavior. Princeton, New Jersey,
US: Princeton University Press.

Yao, J., Ma, C., & He, W. P. (2014). Investor Herding Behaviour of Chinese Stock Market. International Review of Economics & Finance, 29, 12-29.

Research Articles


How to Cite
POKAVATTANA, Nitis; SETHJINDA, Thananporn; TANGJITPROM, Nopphon. The Over-Reaction Effect in the Stock Exchange of Thailand: An Empirical Study. Journal of Community Development Research (Humanities and Social Sciences), [S.l.], v. 12, n. 3, p. 92-106, july 2019. ISSN 2539-5521. Available at: <>. Date accessed: 20 july 2019. doi: