فصلنامه بورس اوراق بهادار
پیاپی 45 (بهار 1398)

The capital market, is in charge of equipping, attracting financial resources and directing funds toward productive and employment activities, also plays the role of financing for enterprises and economic institutions. Listing new companies brings numerous benefits to them. Therefore, in this research, the financial performance of the companies listed in Tehran Stock Exchange and Iran Fara Bourse was evaluated using the financial ratios index. For this purpose, the average of each of the financial ratios for the three-years period before the initial offering and the three-years period after the initial offering in the capital market was calculated and then using the paired comparison test(T test), we measured the changes in each of the financial ratios during the periods mentioned. In order to study each group of financial ratios, a hypothesis was developed and a pair comparison test(T test) was applied to each of the existing financial ratios. The results of this test did not substantiate any changes in financial ratios during the periods considered.

In recent decades phenomena based on inefficiency have been observed in various international stock exchange markets. The phenomena such as extreme fluctuations in prices, price bubbles, falling price, calendar effects, differences in the return on stocks of small and large companies, and the difference in return on equity and growth, all reflect market inefficiencies and the absence of a balance between price and fundamental variables. It is anticipated that the synchronization of stock prices and the risk of falling stock prices would have an effect as well as herding behavior as a mediator on the relationship of this variable. The sample companies in this study belong to the companies accepted in the Tehran Stock Exchange in the period from 2012 to 2016. In this study Chen et al. (2001) and Kim et al. (2011) models for stock price crash risk and Piotroski and Roulstone (2004) models for measuring the Stock price synchronicity and Lakonishok model (1992) to measure herding behavior. The findings show that there is no significant relationship between stock price synchronicity and the stock price crash risk, the result of the second hypothesis of the research is based on the mediating role of herding behavior in the relationship between stock price synchronicity and stock price crash risk.

The aim of this study is to investigate the role of corporate governance in the timely of reporting the restated financial information and the effect of corporate governance on the relation between restated financial information and abnormal returns. A sample of 160 list companies in Tehran Stock Exchange for the period of 2012-2017 has been selected. The results show that there is a direct relationship between independence of the board of directors, Chief Executive Officers (CEO) change and auditor change with Timely of the restated financial information. Other results show that there is no relationship between duties duality of CEO and Timely of the restated financial information. The results show that after the date of restatement, Timely of the restated financial information is effect on abnormal returns and unexpected earnings is not important for this result. other results show that CEO change is influence on the relationship between abnormal returns and season information after date of restated financial information. Eventually the results show that in firms by Timely of the restated financial information that reports season information after date of restated, the change of CEO is not influence on the relationship between unexpected earnings and abnormal returns. This result can be accepted in the firms that do not reports restated financial information by timely.

The relationship between financial and commodities markets is a challenging issue among regulators and investors, where the volatility of a market could affect other markets. This article’s goal is analyzing the long-term relationship between six-year daily returns of alternative markets such as crude oil, dollar, gold and Tehran stock market index. We take advantage of VAR-GARCH to model markets returns and subsequently to show relationship between these markets and using impulse response functions to describe the reaction of a market in response to a pulse in other markets. The results express that Tehran stock market total return index (TEDPIX) return respectively is depend on its previous lag, crude oil, gold and dollar returns and they are more sensitive to their shocks than market news.response to a pulse in other markets. The results express that Tehran stock market total return index (TEDPIX) return respectively is depend on its previous lag, crude oil, gold and dollar returns and they are more sensitive to their shocks than market news.

In recent years, the attention of researchers has focused on the issue of international communications between economics and financial markets in different countries, and the impact of changes in the global financial markets on the domestic capital markets volatility in each country. The study of the effect of Malaysia and Turkey Stock Exchanges volatilities on Tehran Stock Exchange were examined in this paper. The annual data for doing this study were collected from internal and external data bases and tested using the Eviews and Microfit soft wares in the period from 1376-1395. The experimental results of this study show that the effect of Malaysia stock exchanges and Turkey stock exchanges volatilities on the Tehran Stock Exchange in the short term and long term was approved. In this study, as well as to the hypothesis that the effect of exchange rate and inflation on Tehran Stock Exchange the results of the study, confirmed the relationship.

The phenomenon of whistleblowing is one of the concepts that has been considered by many researchers in the audit profession in recent years. This phenomenon means disclosing illegal and unethical activities in organizations. The auditor’s cynicism of the organization and the feelings of dependency on it can affect the whistleblowing of violations. The aim of this paper is to investigate the effect of organizational cynicism and professional commitment on this phenomenon. The theoretical foundations of the research are based on library studies and research data has been collected by questionnaire; and also, hypothesis testing is used by structural equations by lizrel software8.8. The sample size of this study is 192 auditors of audit firms, who work in IACPA and audit organizations. Findings of the research indicate that professional commitment has a direct and positive effect on whistleblowing. Also, the auditor's cynicism has a direct and indirect negative effect on professional commitment and whistleblowing.