A review of investors’ reaction to unexpected events in Tehran Stock Exchange

Document Type : Research Paper


1 Associate Prof., Business Management, Tehran, Iran

2 MSc., Business Management, Yazd, Iran


Unexpected economic and political events are considered important elements impacting investment decisions of the investors during stock transactions and changing the stock price in desirable or undesirable ways. The current study aims to provide a review on investors’ reaction to unexpected events in Tehran Stock Exchange market. For this purpose, the daily returns of the period spanning 1386-1391 have been reviewed as a sample of  investors’ behavior based on the uncertain information hypothesis. The findings indicate that occurrence of unexpected events will increase returns oscillation. Also, the results show that, regarding the desirable news, the reaction of investors corresponds to prediction of uncertain information hypothesis, that is, the unusual revenue of stocks after desirable information is positive, but it would not verify the hypothesis of the prediction of undesirable news. In other words, behavior, after the desirable news, will follow the uncertain information hypothesis; however, after the bad news, it would not follow this hypothesis. Also, for both, desirable and undesirable events, moderating and adjusting the stock price have gone downward.


Main Subjects

Abde Albaghi, A. M. & Badri, A. (2010). An introduction on financial econometrics. Tehran: Nas Publications. (in Persian)
Ahmed Heshmat, N. (2012). Non-professional investors' behavior: an empirical study of female Saudi investors. International Journal of Commerce and Management, 22 (1): 75-90.
Ajayi, R. A. & Mehdian, S. (1994). Rational Investors'reaction to uncertainty: evidence from the world's major markets. Journal of Business Finance & Accounting, 21 (4): 533-545.
Al-Tamimi, H. (2006). Factors influencing individual investor behavior: an empirical study of the UAE financial markets. The Business Review, 5 (2): 225-233.
Badri, A. & Asilzadeh, M. (2011). Cross-reactive and amplitude Prices: Evidence from Tehran Stock Exchange. Accounting and auditing research, 9 (3): 56-73. (in Persian)
Brown, K. D., Harlow, W. V. & Tinic, S. M. (1988). Risk Aversion, Uncertain Information, and Market Efficiency. Journal of Financial Economics, 22 (2): 355−385.
Brown, K. D., Harlow, W. V. & Tinic, S. M. (1993). The Risk and Required Rate of Common Stock Following Major Innovations. Journal of Financial and Quantitative Analysis, 28 (1): 101−116.
Daniel, K., Hirshleifer, D. & Subrahmanyam, A. (1998). Investor Psychology and Security Market Under-and Overreactions. Journal of Finance, 3 (6): 1839–1885.
Debondt, W. F. & Thaler, R. H. (1985). Does The Stock Market Overreact? Journal of Finance, 40 (3): 793−805.
Debondt, W. F. & Thaler, R. H. (1987). Further Evidence on Investor Overreaction And Stock Market Seasonality. Journal of Finance, 42 (3): 557−581.
Flahpoor, S., & Abdullahi, Gh. (2011). Identifying and weighting bias of investor behavior in Tehran Stock Exchange market: AHP approach. Financial Research, 13 (31): 99-120. (in Persian)
Jahankhany, A., Noferesti, M. & Qharaguzloo, F. (2009). Review of excessive confidence of investors and trading volume in the Tehran Stock Exchange. Prespective of Management, 30 (8): 105-123. (in Persian)
Khajawi, SH. & Ghasemi, M. (2006). Hypothesis of effective market and Behavioural finance. Quarterly of Financial Research, 20(7): 49-69.
(in Persian)
Lashkari, M. & Mortazi, H. (2011). Theory of behavioral finance and its impact on the volume of investment in the Tehran Stock Exchange. Strategy magazine, 26: 48-63. (in Persian)
 Maditinos, D. I. & Sevic, Z. (2007). Theriou, Nikolaos G.; Investors’ Behaviour in the AthensStock Exchange (ASE). Studies in Economics and Finance, 24 (1): 32-50.
Muradoglu, G. & Harvey, N. (2012). Behavioural finance: the role of psychological factors in financial decisions. Review of Behavioral Finance, 4 (2): 68-80.
Nazari, M. & Farzanegan, E. (2011). Irregnaritics of periods in returns of Stock Exchange of Tehran. (Nonparametric bootstrap sampling method). Financial Research, 13 (31): 147-167. (in Persian)
Raai, R., & Flahpoor, S. (2004). Behavioral finance, a different approach in the financial area. Financial Research, 18(6): 77-106. (in Persian)
Ritter, J.R. (2003). Behavioral Finance. Pacific-Basin Finance Journal, 4 (11): 429-437.
Saadi, R., Gholipoor, A. & Gholipoor, F. (2010). Consideration of impact of investors’ personality and cognitive errors on their investment in the Tehran Stock Exchange. Financial Research, 12 (29): 41-58. (in Persian)
Sedghi Khorasgani, H. (2005). The identification and characterization of the dominant styles Tehran stock market investors, University of Imam Sadiq, Tehran, MSc thesis. (in Persian)
Shajari, H. & Imam, S. (2012). Identification and analysis on factors affecting the decision making investors in the Tehran Stock Exchange. Commercial Consideration, 53: 1-13. (in Persian)
Talane, A., Mahmoodi, M. & Sharafi, K. (2013). Abnormal trading volume of content companies in Tehran Stock Exchange. Financial Research, 16 (1): 1-16. (in Persian)
Talangi, A. (2004). Confrontation of modern financial theory and behavioral finance. Financial Research, 6 (1): 3-25. (in Persian)
Venezia, I. & Sharpia, Z. (2007). On the Behavioral Differences between Professional and Amateur Investors after the Weekend. Journal of Banking & Finance, 31 (5): 1417-1426.
Yousefi, R. & Shahrabadi, A. (2009). Evaluate and test the behavior of investors in the Stock Exchange. Management of development and evolution, 2: 57-64. (in Persian)