Univrsity Of Tehran Press Financial Research Journal 1024-8153 20 3 2018 11 22 Investigating Some of Effective Factors on Spoofing Manipulation in Iranian Stock Market Investigating Some of Effective Factors on Spoofing Manipulation in Iranian Stock Market 327 342 68611 10.22059/frj.2018.260795.1006685 FA Mohammad Nadiri Assistant Prof., Department of Financial Management, Faculty of Management & Accounting, University of Tehran, Tehran, Iran 0000-0003-1655-3489 Seyed Mohammad Alavi Nasab Assistant Prof., Department of Financial Management, Faculty of Management & Accounting, University of Tehran, Tehran, Iran Moslem Peymani Assistant Prof., Department of Financial and Banking Management, Faculty of Management & Accounting, Allameh Tabataba’i University, Tehran, Iran Reihaneh Rabiee Ph.D. Candidate, Department of Financial Rights, Faculty of Management & Accounting, University of Tehran, Tehran, Iran. Journal Article 2018 06 24 Objective: There is a large theoretical literature regarding stock market manipulation. However, empirical evidence of manipulation remains scare especially in emerging markets like Iran. So, it is vital to detect and prevent. Manipulation distorts prices, thereby reducing market efficiency and harms public confidence. Distorted prices increase market volatility and risk. This study empirically investigates which firms are more susceptible to successful deceptive manipulation. Methods: We collect the data set consisting of manipulation cases of entering spoofing order in Iranian stock market in two periods. In the first three-month period, the index was downward and in the second one, it was upward. Panel Logit regression was used to determine and interpret results. Results: The regression results showed that small firms, with high trade volume, low information transparency, high information asymmetry and high volatility are more prone to stock price manipulation. Indeed, there is an inverse relationship between manipulation and fluctuation index. Conclusion: Index change is an effective variable on stock manipulation. Manipulation is more probable in bear market, because most of the stocks are upward in bullish markets and there are fewer motives for stock manipulation.   Objective: There is a large theoretical literature regarding stock market manipulation. However, empirical evidence of manipulation remains scare especially in emerging markets like Iran. So, it is vital to detect and prevent. Manipulation distorts prices, thereby reducing market efficiency and harms public confidence. Distorted prices increase market volatility and risk. This study empirically investigates which firms are more susceptible to successful deceptive manipulation. Methods: We collect the data set consisting of manipulation cases of entering spoofing order in Iranian stock market in two periods. In the first three-month period, the index was downward and in the second one, it was upward. Panel Logit regression was used to determine and interpret results. Results: The regression results showed that small firms, with high trade volume, low information transparency, high information asymmetry and high volatility are more prone to stock price manipulation. Indeed, there is an inverse relationship between manipulation and fluctuation index. Conclusion: Index change is an effective variable on stock manipulation. Manipulation is more probable in bear market, because most of the stocks are upward in bullish markets and there are fewer motives for stock manipulation.   https://jfr.ut.ac.ir/article_68611_73becdf0616b942da5e73eea29b9796f.pdf