علی نجفی مقدم

It is very important to distinguish how the volatility in the return of assets occur. For this reason, in recent years, realized volatility and frequencies of daily volatility recognition studies have been developed. This study uses stock prices of 30 big companies of Tehran Stock Exchange during the years 1390 (2011) to 1394 (2016) and calculates the realized stock volatility during trading days using the HAR-CJ model to examine the effect of size and intensity of price jumps in predicting index volatility. The results showed that the development of HAR-CJ and HAR-RV-CJ models using the size and intensity of jump did not have a significant effect on improving the index volatility prediction but, to a small extent, the model prediction performance Adjusts for index volatility. Also, using intraday jumps instead of daily jumps, does not improve the performance of the prediction model.

The general goal of this research is to provide a model to explain the behavior of real investors in the Iranian capital market with an emphasis on local indicators.

The research is done using applied and qualitative method based on grounded data theory technique. Data were collected through semi-structured interviews and theoretical sampling continued until the categories were saturated. Then, based on the theoretical systematic approach of Strauss and Corbin in the three main steps of open, central and selective coding, the paradigm model of investors' behavior was presented with emphasis on local indicators.

The findings showed that the central category of the paradigm model and the causal conditions affecting the behavior of investors, in terms of background and involved factors, are placed in two main groups: behavioral-psychological and demographic factors, which are 19 categories of behavioral and psychological factors and demographic factors. 5 categories have the most importance on the behavior of investors.

Originality / Value: 

In many studies, only the semi-conscious aspect of the mind and with medical equipment has been addressed. While in this study, the conscious and alert aspects of investors' minds have been analyzed.

This study evaluates the effect of financial policies on stock market investment in financial friction conditions. For this purpose, two models were designed based on financial policies (taxes and government expenditures) and in the period from 1991 to 2017, the short-term dynamic relationship, long-term state and error correction of the models were estimated with the Auto Regressive Distributed Lag (ARDL). The financial friction index is used in this study based on the definition of the interest rate gap (the difference between on the lending interest rate and the deposit interest rate). The results show that in terms of financial friction, fiscal policy had a significant and negative impact on the first model (tax based) and in the second model (based on government spending) a positive and significant effect on the total stock price index. This result is in line with Keynesian view. The financial friction index also had a negative effect on the total stock price index in both models. However, since taxation directly affects corporate liquidity, therefore, in fiscal policy based on tax revenues, the effect of fiscal friction on the dependent variable was more dependent on government spending than fiscal policy. The results of estimating the other variables in the models were that GDP based on Keynesian theory, oil revenues based on support theory and exchange rate in flow-oriented models had a significant and positive effect on the total stock price index.

Considering the importance of disclosing key items in the audit report, the purpose of this study was to investigate the effect of the audit report disclosing key items model on companies' business failure to examine the extent to which disclosing key items in the audit report will be able to reduce The failure of corporate business and investors relying on the disclosure of such information to make decisions in capital market companies.

in this research, the combined research method (qualitative-quantitative) based on Gillers approach is used in data analysis of the foundation (contextual theorizing). For this purpose, a survey of 13 experts and specialists in the auditing profession examined the impact of disclosure of key items in the audit report. The work of companies listed on the Tehran Stock Exchange was presented.

The results led to the formation and presentation of a model that in this model in the qualitative part indicates the existence of 3 categories, 6 components and 31 concept codes. But the target population in a small part was 202 managers and brokers of Tehran Stock Exchange companies. The results in the quantitative part showed that the disclosure of the key items of the audit report has a negative and significant effect on the business failure of the Tehran Stock Exchange companies.

Disclosure of key audit items can not necessarily be considered to increase the decision-making power of external stakeholders, because by auditing and evaluating the company's performance, the auditor can mention various points to the board and directors of companies, their level of knowledge to better align their functions with accounting standards and Strengthen the audit. Therefore, based on this result, it was found that disclosing key items in the audit report according to existing standards can reduce the level of failure of capital market companies' businesses.

Contribution:

 The Knowledge In addition to developing the literature on disclosure of key items in the audit report, this study leads to the right decision of stakeholders and investors to rely on the disclosure of such information to make decisions in capital market companies.

Investors are looking to choose the optimal combination of assets and allocate their wealth among them in such a way that they can achieve the goal of investing (increasing the revenue that can be seized in future periods). The main issue in this study, considering the conditions of high liquidity or low liquidity of companies' stocks and portfolio selection models, is the use of a new tool to select investment portfolio. The statistical sample for 27 companies active in the time domain from the beginning of April 2014 to March 2017 has been considered. The use of asset liquidity index to optimize portfolios using and benchmarking process has made a significant difference in portfolio weights, yields and risk compared to the Markowitz model. Also, the results of calculating the trainer criterion showed that the optimization model obtained from the benchmarking process of the value function has a higher performance than the portfolios obtained from the Markowitz model. .

The purpose of this study was to investigate the effect of exchange rate as an indicator of economic stability on the stability of assets value in Tehran Stock Exchange during the years 1385 to 1397. For this purpose, the current research is included in descriptive research in terms of research method and applied research in terms of purpose. Also, the design of this research is using the post-event approach. Also, in the current research, the panel data model was used to investigate the relationship between the variables. The results of the research showed that the fluctuation of the exchange rate has a significant effect on the first indicator of the stability of asset value, i.e. the book value of assets, at the level of 95%, and this effect is reversed. The effect of exchange rate fluctuation on the second index of asset value stability, which is the market value of assets, is significant at the 95% level. Also, the effect of exchange rate fluctuation on the third index of asset value stability, i.e. the current value of assets, was also negative and significant at the 95% level. Considering the influence of the exchange rate on the indicators of the stability of the value of assets, it is suggested that relying on domestic production and using raw materials available inside the country is one of the solutions to reduce losses caused by exchange rate fluctuations.

Investment efficiency is achieved when the company invests only in all projects with a positive net present value. Of course, this scenario works if the market is complete and there are no incomplete market issues such as incorrect selection and agency costs. Do not haveThe purpose of this research is to apply artificial intelligence algorithm in predicting investment efficiency by emphasizing the role of risk management criteria. For this purpose, the financial information of 139 companies between 2010 and 2019 was used using genetic artificial intelligence and neural network methods. The results indicate the effect of risk management criteria on investment efficiency and also the results showed that the neural network artificial intelligence method has higher power than the genetic artificial intelligence method to predict the investment efficiency of companies listed on the Tehran Stock Exchange.

Risks and hazards in the economic context of a country can affect the country's economic indicators and have a reason for the growth or decline of the index .Risk can be explained as a factor that upsets the balance and changes the situation In emerging economies, one of the concerns of economists is to control existing risks to reduce costs and increase the growth of economi indicatorsIn this study, the effect of financial, economic, international and political risks on the total index of the stock exchange is examined, which, while examining the presence or absence of impact, examines the direction of impact. For this purpose, the modelARDL Quarterly data for the years 1388 to 1398 were used The results in the short and long term are that financial risk has a negative impact on the index and economic and international risk have a positive effect in the short term and in the long term financial risk and economic risk are also negative but international risk. It has a positive effect

One of the most important sources of income for governments in most countries of the world is taxation. The purpose of this study is to review and compare the two strategies of tax collection and exemption from interest on bank deposits. SWOT analysis questionnaire was prepared for both tax collection and exemption modes and was given to ten groups and expert of stakeholders (1041 questionnaire). Scoring was based on the Likert scale and SWOT analysis was ranked based on SPACE Matrix. The results showed that the most important weaknesses and threats for taxation of interest on bank deposits are reducing people's willingness to deposit in banks and increasing investment in unproductive units such as investing in currency, commodities and coins, respectively. The most important weaknesses and threats for tax exemption were the reduction in the cost of money to banks, the reduction in the supply of labor, and the increase in the ultimate desire to consume, respectively. The results showed that in general, the management strategy of taxing the interest on bank deposits in the whole statistical community is aggressive and defensive for tax exemption.