نشریه پیشرفت های مالی و سرمایه گذاری
پیاپی 5 (زمستان 1400)

The purpose of this paper is to predict stock prices using Hybrid GA-SVM Algorithm. Predicting time series such as stock price forecasting is one of the most important issues in financial field. In real life, identifying time series movements in stock price indices is very complex. Therefore, the use of a classical model alone cannot accurately predict stock price indices. Hence, by using combined methods, uncertainty in forecasting can be reduced. In stock price forecasting in financial sector, more than 100 indicators have been created to understand stock market behavior, so, identifying the appropriate indicators is a challenging problem. One of the techniques that has recently been studied for serial forecasting is support regression Vector (SVR) or machine support vector (SVM). This study uses the GA-SVM hybrid algorithm to predict the stock price index. Experimental results show that Hybrid GA-SVM Algorithm provides a more appropriate and promising alternative to stock market forecasting.

Financial Reporting Quality is one of the most important effective factors in decision making of investors. Therfor, The main objective of this study was to Relationship Between characteristics of the Audit committee and financial reporting quality proxied by accrual quality. To Further clarify the mentioned links, this study empiricaly assesses the moderating effect of audit quality. This study is based on a sample consisting of 120 in the companies listed in Tehran Stock Exchange. The sample of the research consists of 120 companies listed on Tehran stoch exchange during the period from 2014 – 2019. This study has applied multiple regression to test hypotheses and EVIEWS 10 software is used for analysis of data. The findings showed that Findings showed that there is a positive and significant relationship between the characteristics of the audit committee and the quality of financial reporting. Also, audit quality has a positive and significant effect on the relationship between the characteristics of the audit committee and the quality of financial reporting.

The purpose of this study was to investigate the effect of momentum on the disposition effect and expected stock returns in the framework of the prospect theory of Kahneman and Tversky (1979) and the mental accounting theory of Thaler (1985). The statistical population of this research included all companies incorporated in Tehran Stock Exchange between 2008 and 2019 from which102 companies were selected as the sample using the systematic elimination method. Multiple regressions were used to test the hypotheses of the research. The results of testing the research hypotheses indicated that momentum influenced the disposition effect. Another result showed that momentum affects the expected stock returns. Moreover, after controlling the disposition effect, the impact of momentum on the expected stock returns was reduced. In other words, the short-term, medium-term and long-term momentum coefficients are lower when the disposition effect is controlled, which means that by controlling the inclination effect of stocks, the momentum effect on the expected stock decreases

Moral hazard is created as a result of factors such as delegated powers to managers and their motivation to use these powers for self interest and can have consequences such stock illiquidity and devaluation of the company. The main purpose of this study is to investigate the relationship between moral hazard with stock illiquidity and firm value with emphasis on corporate governance mechanisms. The research data were collected through the financial statements of 180 companies listed on the Tehran Stock Exchange over a period of 14 years from 2007 to 2021. Panel data and multiple regression model were used to test the research hypotheses. The results of the study showed that the moral hazard of managers has a positive and significant effect on the illiquidity of stocks Also, the moral hazard of managers has a negative and significant effect on the firm value.The interactive index of moral hazard and corporate governance has a negative and significant effect on stock illiquidity and has a positive and significant effect on firm value. Therefore, moral hazard of managers has undesirable consequences such as devaluation of the company and stock illiquidity, and corporate governance mechanisms weaken the destructive consequences of moral hazard of managers. By being aware of the adverse consequences of moral hazard of managers and also the effect of corporate governance mechanisms on weakening the severity of moral hazard, it is possible to make optimal decisions to control moral hazard by strengthening corporate governance mechanisms and serving the interests of stakeholders, especially shareholders.

Developed industrialized countries use bilateral investment treaties to protect the rights of companies when investing in uncertain markets but developing and emerging countries are concluding BITs to attract more foreign direct investment and compete for a larger share of FDI. a range of developing and newly industrialized countries with a sample of 156 in a 15-year period from 2004 to 2019 with an average of 3 new foreign investments per year were selected and analyzed using binary logistic regression. The results showed: a) The effect of political instability variables and BIT stringency is not significant in non-interactively, but interactively with increasing political instability, BITs reverse the priorities of MNEs to choose majority ownership over minority ownership. b) At higher levels of political instability, greater BIT stringency increases the likelihood of increasing MNE selection from stocks. C) The stringency of BIT acts to moderate the relationship between political instability and the choice of sub-ownership in host countries. And more stringent BIT, as political instability increases, encourages the MNE to choose majority ownership over minority. Thus, more stringent bilateral investment treaties encourage multinational corporations to choose majority stocks as political instability increases.

The results of research in the field of financing based on a behavioral approach suggest that investors may be irrational; As a result, investors' cognitive bias or psychological factors can influence their decisions. Thus, stock price volatility depends not only on the intrinsic value shown by accounting information, but also on the irrational behavior of investors, which can be measured by the investor's inclinations. Therefore, considering the importance of this field, the present study presents a model of investors' tendencies with emphasis on psychological factors with fuzzy Delphi and DEMATEL methods. This research is a data foundation research. Also, this research is a type of mixed research in which two approaches used in behavioral sciences, namely quantitative and qualitative, are used. The statistical population of this research is divided into two parts. The first part of the statistical population consists of financial and investment experts, which includes experts in this field, who are consulted to determine the dimensions, components and indicators, and the second part of the statistical population includes all university professors who have a doctorate in finance. And are investments. Using fuzzy Delphi method, the optimal criteria of investors 'tendencies with emphasis on psychological factors were extracted and the final model of the levels of optimal factors of investors' tendencies with emphasis on psychological factors was also drawn. Also, the effect and influence of factors on each other were evaluated using DEMATEL method.

Risk exists where there is an opportunity for return. The application of risk management strategies is a critical issue; Because it prevents the occurrence of crises. Despite the risk management, if a certain crisis occurs, the resulting damages and losses will be minimized. This issue is much more important in business, because it reduces financial losses and prevents wasting time to achieve the main goals of the business. One of the most important risks that businesses face and must be managed is competitive risk and the risk of reputation or branding in business. If these risks are not managed in business, they can be potential threats and unwanted effects on the credibility and reputation of the company. have Halal branding is one of the things that is important in gaining the market and remaining in the competitive environment of global trade. The growing Muslim population, economic growth and development in Muslim countries, the emergence of potential halal markets are among the factors influencing the growth of the halal industry in the world. The purpose of this research is to express this fact that in the new conditions created, in addition to the components of the survival triangle (cost, quality and performance) which is a necessary condition for the survival of the business, to the structures of the halal triangle (Sharia, acceptability and health) ) is needed as a sufficient condition in today's competitive environment.