فصلنامه بورس اوراق بهادار
پیاپی 9 (بهار 1389)

Mutual funds are one of the most important financial institutions which play an undeniable role in transferring excess funds toward companies. In Iran, for the first time and under the Provisions of the securities market act (ratified in 2005), mutual funds were established, launched and introduced to capital market realm since March 2008. The main objective of this study is to provide empirical finding to answer this question that whether performance of mutual funds is good enough in comparison with market return or not. Risk-adjusted performance measures which were applied in this research are: sharp ratio, Jensen's alpha, Treynor ratio and Sortino ratio for the period of March 2008 up to the July 2010. In accordance with the findings of the research, with ANOVA, there is not significant difference between risk-adjusted performance measures of mutual funds and the market return. Also, based on the Sharp ratio, Treynor ratio and Sortino ratio, there is no significant difference between the performances of mutual funds and the market return. But, Jensen's alpha didn’t refuse existence of any significant difference between different mutual funds.

In this study, the effect of audit firm rotation on the audit report quality of listed companies in Tehran stock exchange has been studied. In fact, this research is a response to this question: "what is the effect of the audit firm rotation on the audit quality? The meaning of audit firm rotation is transfer and change of auditors in a maximum 4 years period and audit quality is the sum of competency (ability to explore the misstatement), independence of auditor (incentive of reporting the explored paint). This is a measurement and the required data is gathered from document searching in the gathered financial reports. In this way, the financial data of the stock exchange companies which experienced the audit firm rotation was studied. The analysis of data and the test of hypothesis in the years of 1999 to 2006 shows that the audit firm rotation does not effect on audit quality.

This study investigates the effect of Institutional Ownership on the firms performance, using a data sample representing 78 companies during1381-1386. For measuring the effect of Institutional Ownership Ratio on the firms performance, we used regression model. In this study, we used Tobin's Q and ROE standard as the two performance measures, and also the Institutional Ownership as an independent variable. we investigated the firm performance and ownership effects on each other using four control variables: (leverage, capital expenditure, market risk and firm size) we also used K-S, multiple R, t and Durbin Watson tests. The results demonstrate significant evidences of a positive relationship between institutional ownership and firms performance. This means that, firm's Institutional Ownership had a significant impact on the Tobin's Q and ROE. We also found a significant relationship between ROE and leverage. However, we did not find significant relationship between firms performance and capital expenditure, market risk and firm size.

Tehran Stock Exchange, following the reopening in 1989, experienced a series of up and down trends in its operations which were generally considered as the nature of the market and the consequences of the market events. But, we are sometimes witness to a set of unexpected intense reactions to those events took place across the whole market. The stock market crash of 2004 may be included as a same reaction. Here, we have examined the hypothesis of "The Existence of Price Bubble in Tehran Stock Exchange during a Three-Year Period of 2003-2005". However, the existence of price bubble is examined by using the stationary test for P/E ratio and the results show the existence of price bubble in 280 stocks from among a number of 324 companies examined by this method. So, the dominance of a price bubble over the TSE stocks is confirmed.

The aim of this study is to investigate the relationship between Corporate Social Responsibility (CSR) and Organizational Commitment (OC) with conservatism (CSVT) in financial reporting of the listed companies in Tehran Stock Exchange. In this research, for measuring of conservatism was used Givoly & et al model (2007) in period of 2003-2009, for collecting data concerning CSR, we used Singhapakdi, Vitell, Rallapalli & Kraft's standard questionnaire (1996) and for determining the OC, Hunt, Wood & Chonko's standard questionnaire (1989) we had because of its high validity and reliability. Sample research includes 115 accepted companies in TSE in the years between 2002-2008. For testifying the hypotheses, we applied the regression models. Findings show the relationship among ethical factors (CSR & OC) and conservatism has been positive, but only relationship between CSR and conservatism is statistically meaningful. However, results show that about 24% of conservatism variation in investigated companies has been affected by ethical factors without control variables and this has increased to 31%. Among research variables, CSR variable has been of the most explanatory power (21%) on conservatism. Concerning the control variables, results show that bigger companies and growth stocks have conservative financial reporting (positive relation) and the relation between financial leverage and conservatism is negative.

Nowadays, competition has a fundamental role in auditing profession. Hence the time and cost reduction and auditing quality enhancement are necessary via application of management principles and techniques. The statistical population includes the companies listed in Tehran Stock Exchange (1383-1386). For data analysis, the new model of neural network is used and the input removal method is applied to determine the significance of relationship between variables. The results revealed that the inventory turnovers, the ratio of total liabilities to total assets, the ratio of accounts receivable to total asset and the qualifications of last year report had meaningful (significant) effect on the issue of qualified audiding report, considering the nine variables supposed to significantly affect the issue of qualified auditing report.

The purpose of the study is investigating the relationship between advertising expenditures and firm value in Tehran Stock Exchange (TSE). In this study, the pool data from 100 companies are analyzed by the use of consolidated regression for the period of 2004-2008. The first hypothesis analyses the relationship between ratio advertising expenditures to total assets and firm value. The second hypothesis investigates the relationship between ratio advertising expenditures to net sales and firm value. The results show that none of the hypotheses are confirmed. In other words, there is no significant relationship between ratio advertising expenditures to total assets and firm value. However, no significant relationship is observed between ratio advertising expenditures to net sales and firm value.