عدم تقارن اطلاعاتی

Block trading is used by investors in the capital market because it provides company-specific information, which is a tool for optimal stock pricing. Additionally, the media can bring the interests of managers and shareholders closer together by publishing company-specific news, thereby reducing information asymmetry, increasing stock price awareness, and decreasing stock price coincidence. Therefore, the purpose of this study is to investigate the moderating role of media coverage in the effect of block trading on stock price synchronicity. The statistical population of this research consists of companies listed on the Tehran Stock Exchange from 1393 to 1401, which were selected through systematic deletion of data from 100 companies, including 11,237 block transactions for review, experience, and analysis. The results of the Multivariate regression model based on composite data showed that the number and block trading ratio have a positive effect on stock price synchrony. Moreover, media coverage as a moderator variable in the effect of block trading ratio has a negative effect on stock price synchrony. These findings emphasize the inefficiency and lack of transparency of information in the Iranian stock market, which prevents the timely incorporation of company-specific information into stock prices.

The lack of reliable information disclosure contributes to information asymmetry, which in turn raises the equity cost of capital. Voluntary information disclosure can mitigate unsystematic risk and this reduction can enhance investor confidence through financial signaling. When investors perceive a company as more resilient to specific market fluctuations, the company’s beta—a measure of systematic risk—tends to decrease. This shift in risk perception can ultimately lower the equity cost of capital. Furthermore, when a company improves the quality of its disclosures, it not only affects its own valuation, but can also influence the broader market. In this sense, the disclosure practices of one company can shape public perception and impact the risk assessments of other companies as well.  This study explored the mediating role of information asymmetry in the relationship between voluntary information disclosure and the equity cost of capital, utilizing the Capital Asset Pricing Model (CAPM). To achieve the research objectives, a sample of 159 companies listed on the Tehran Stock Exchange (TSE) from 2018 to 2023 was selected. Panel data analysis and multivariate linear regression were employed to test the hypotheses. The findings indicated that voluntary information disclosure did not significantly affect the equity cost of capital. Moreover, the mediating variable of information asymmetry also did not significantly influence the relationship between voluntary information disclosure and the equity cost of capital. This lack of significance might be attributed to the generally low level of voluntary disclosure, inefficiencies within the Iranian capital market, and the limited scope of disclosed information. Additionally, the absence of financial analysts and insufficient investor attention had hindered voluntary disclosures from effectively reducing information asymmetry in the capital market.

There are two distinct perspectives regarding the impact of real earnings smoothing on labor investment efficiency through its effect on information asymmetry. On one hand, based on signaling theory, real earnings smoothing can reduce information asymmetry and enhance labor investment efficiency. On the other hand, the opportunistic managerial view highlights the opposite effect. Given this context, the present study aims to investigate the impact of real earnings smoothing on labor investment efficiency, with information asymmetry acting as a mediating variable.
 
This study falls under the category of applied research due to the applicability of its findings in the decision-making process. The data utilized in this research were collected based on past real information, making it an ex-post-facto study. Additionally, this research is descriptive-correlational in nature, with the primary objective being the examination of relationships between the research variables. To this end, considering the conditions and constraints imposed on the research population, a sample of 106 companies listed on the Tehran Stock Exchange was selected, and the hypotheses were tested using multivariate regression models.
 
The results indicate that an increase in the level of real earnings smoothing leads to improved labor investment efficiency. Furthermore, information asymmetry mediates the relationship between real earnings smoothing and labor investment efficiency, where real earnings smoothing, by reducing information asymmetry, contributes to greater efficiency in labor investment.
 
Based on the findings, it can be concluded that company managers use real earnings smoothing to convey hidden information. This information reflects the company's future outlook, which, through consistent earnings smoothing over the years, presents a clear and positive projection of the company's future to investors and creditors. This supports the view that smoothed earnings are indicative of a bright future for the company, as these earnings are perceived by investors and creditors as sustainable. In fact, by using signaling tools, managers reduce market information asymmetry regarding the company’s stock price, enabling the company to secure the necessary financial resources for labor investment and make efficient decisions. Therefore, based on the signaling theory of private information, it can be concluded that real earnings smoothing conveys managers' private information regarding the company's future revenues, thereby reducing the information asymmetry between companies and external capital providers, ultimately leading to greater labor investment efficiency. This research contributes to the growing body of literature on real earnings smoothing and labor investment efficiency, highlighting the importance and positive impact of real earnings smoothing, while also emphasizing the need for further investigations due to the lack of understanding regarding managerial motivations behind real earnings smoothing.

The information-based model is one of the prevalent frameworks in the market microstructure literature, examining trader behavior in the presence of information asymmetry and its subsequent impact on price formation. Information asymmetry significantly contributes to market inefficiency, manifesting in traders' transactions and orders. Informed traders, possessing knowledge of an asset's intrinsic value through access to comprehensive market information, engage in high-volume transactions and orders to maximize their informational advantages. These value-relevant orders influence the actions of other market participants and consequently affect market prices. Given the critical role of information asymmetry and its effects on traders' order behavior, the study of orders—rather than mere transactions—has gained prominence. Analyzing traders' behavioral patterns through their order prices, volumes, and types provides a clearer understanding of the price effects resulting from market participants' decisions. Considering the price impact of orders and the significance of the secondary market for Islamic treasury bills as a pivotal tool in the central bank's monetary policy and government financing, this study aims to investigate the price effects of order flow on the price fluctuations of Islamic treasury bills in the market.
 
In this article, according to the price effect of orders in the market, the order flow imbalance variable that shows the changes in supply and demand volume in the first line of the order book has been used. Therefore, the vector autoregressive model has been used to investigate the effect of order flow imbalance on treasury bill price changes. Therefore, to check the price effect of orders, 17 symbols of treasury bills in the over-the-counter market from 2021 to September 2023, which had the most trading days compared to other treasury bills, were used. Therefore, in this research by using the vector autoregressive model and analyzing it through the impulse response function, the effect of order flow imbalance on price changes is investigated in three categories of treasury bills with different maturities to investigate the impact of information asymmetry on orders.
 
According to the findings obtained in this research, the order flow imbalance variable in long-term maturity treasury bills had a greater effect on price changes. Moreover, based on the analyses conducted using the impulse response function, in the event of a shock, the effect of order flow imbalance in long-term maturity treasury bills will remain for extended periods and affect price changes. However, the magnitude of the shock's effect on price changes is much greater than that of the order flow imbalance variable.
 
Therefore, it can be concluded that in long-term maturity treasury bills, the effect of information asymmetry in the order flow is greater than the other bills and can lead to price volatility. Hence, traders should pay more attention to the supply and demand volume of orders and other factors to prevent potential losses.

The main purpose of investigating the effect of classification shifting on investment efficiency with respect to the role of information asymmetry. In order to investigate this research, two hypothesis have been developed and to test the hypotheses, linear regression patterns based on panel data method have been used. To this end, financial information issued in financial statements of 191 companies registered in tehran stock market for the years of 2016-2021 are used. The present research is applied in terms of the purpose and in terms of purpose and in terms of the method and nature are of the type of correlation. Considering that the data in question are real and historical data, The research is classified as post-event. Excel and EViews 10 software were used to analyze the observations. Findings obtained from the study and testing of research hypotheses showed that classification shifting has a significant and inverse effect on investment efficiency. Also, information asymmetry has a significant and inverse effect on the relationship between classification shifting and investment efficiency.

The asymmetry of information between management and external people causes more conservatism in financial reporting. Conservatism in turn reduces managers' motivation and ability to manipulate accounting information, thus reducing agency costs caused by information asymmetry. In the present study; in addition to examining the effect of information asymmetry on stock returns, the effect of conditional conservatism on the relationship between information asymmetry and stock returns in companies listed on the Tehran stock exchange is also discussed.

In such a way that the researcher, after planning the theoretical foundations and hypotheses of the research, through systematic elimination sampling; he chose the number of 114 companies admitted to the tehran stock exchange in a period of seven years (1394-1400) as a statistical sample and after extracting the necessary data; to test the hypotheses, multiple linear regression model was used using Eviews software.

Research findings; while confirming the hypotheses, he concluded that, firstly, information asymmetry has a positive and significant effect on stock returns, and secondly, conservatism does not directly affect stock returns, but its increase weakens the intensity of the direct relationship between information asymmetry and stock returns will be.

Therefore, when the information asymmetry of the companies is high, the managers of the companies will create a conservative estimate of the market information. Hence, information asymmetry can potentially lead to big mistakes or risks.

Several empirical studies have tested the relationship between information asymmetry and the cost of equity capital and have reported conflicting results. Some studies evaluate this relationship as positive, some as negative, and some as insignificant. The discovery of divergence factors has an effective role in managing information asymmetry, the cost of equity capital, and shareholder wealth. In this study, this issue is followed by the meta-analysis approach. This meta-analysis was carried out in seven stages. For this meta-analysis, 36 studies published between 1986 and 2022 from journals with an H index at least equal to 1 of SCOPUS were used. The number of samples is 260 tests which were extracted from the mentioned studies. Using CME2 software, divergence test, and one-sample t-test with random effects approach in addition to testing 12 hypotheses, the robustness check of the results was tested based on 18 categories of analysis, of which 15 categories confirmed the robustness. The results showed that information asymmetry affects the cost of equity capital. All dimensions of information asymmetry affect the cost of equity capital, except analysts’ quality and income volatility. In addition, information asymmetry has a positive effect on all dimensions of the cost of equity capital.

This research examines the usefulness of the management comentary for the first time in Iran from the view of users, preparers, and regulaters. In order to collect the research data, first, based on the related literature and theoretical foundations, hypotheses related to the usefulness of the management comentary were developed. Then, the data related to the views of the three groups in 2021 were collected and the research hypotheses were analyzed using the one-sample Wilcoxon signed rank test. The main findings show that the primary users of financial reports do not consider the current management comentary useful when making decisions. Also, the preparers of the management comentary do not consider this report useful in terms of not increasing the direct and indirect costs of the company and better fulfilling the responsibility of the company to the stock exchange; but they do not consider this report useful in terms of reducing the cost of financing and increasing the legitimacy of the company. In addition, regulaters do not consider this report useful in terms of increasing information efficiency, liquidity of the stock market and increasing the number of investors and analysts. The findings can inform companies and regulaters (Securities & Exchange Organization and Audit Organization) in relation to the usefulness of the current management comentary and the necessity of any revision and updating of guidelines or standards related to its preparation.

This study seeks to investigate the effect of variables and data related to people's social network on their credit score. In this study, two main goals are pursued: reducing information asymmetry and increasing financial inclusion. Achieving the above goals is done by finding meaningful information about people's social data to measure how such data affects their credit score. The basic hypothesis of this study is that people with a high credit score have social relationships with people who are similar and of the same age. A data set of more than 300,000 loans that have been paid by an Iranian bank to real people has been used to confirm and explain the effect of social network variables on credit score. In order to determine the variables of the study, an in-depth interview was conducted with a number of banking experts and people actively involved in the field of credit scoring, and at the end, the variables were determined and classified into three categories: financial, behavioral, and social. The study continued with the logistic regression method and finally with various regression models based on deep machine learning, including gradient. The results of the analyses conducted using the logistic regression method show that, statistically, people's social variables can predict the probability of their loan default. The results of machine learning algorithms also indicate that social network information can significantly improve the performance of loan default prediction.

Given the importance of stock price fluctuations after the initial public offering for investors,the important factors that cause these fluctuations were examined. For this purpose, the political relations of companies with the government(using the methods of company size factors and the percentage of government ownership)and information asymmetry(using the difference in the offer and sale price range)were investigated that To examine the relationship between political communication and stock price volatility by comparing the means of two independent groups and Multivariate regression method was used to investigate the relationship of information asymmetry.Also,to examine the more accurate dimensions of this relationship, to examine the control variables of supplier reputation and credibilit(using three registered capital characteristics relative market share of initial supply and Number of managed initial public offerings)institutional ownership,earnings management, audit quality and number of shareholders.Findings show that companies'political relations with the government do not affect short-term stock price fluctuations,but these fluctuations in the long run are less for companies with political relations with the governmen (company size factors)than companies without connections. It is political Also, increasing information asymmetry increases stock price volatility after initial public offerings in the long run, but is not effective in the short run.Also, the reputation and credibility of the supplier does not affect price fluctuations, which indicates the lack of attention of investors in Iran at the time of initial public offering to the reputation and credibility of the supplier and the reputation and credibility of the supplier can not affect investors'decisions unlike research in other countries.

This study aims to investigate the weekend effect on the trading speeds higher than usual on traders' cumulative abnormal returns around seasonal earnings announcements. The sample of the study consists of 161 companies listed in Tehran Stock Exchange, covering a period of five years from the beginning of 2013 to the end of 2016. The results of this study show that in the time period of one month before and after the quarterly earnings announcements, trading speeds higher than usual of traders on Tuesday and Wednesday in the first quarter and in the third quarter of the year are higher than in the second quarter. Thus, it can be said that as the end of the fiscal year approaches and the speed of transactions increases, information asymmetry increases and leads to abnormal returns. existence of high trading speed of stocks leads to development of the theoretical framework of information asymmetry

The purpose of this article is to investigate the effect of corporate social responsibility (CSR) on the speed of adjustment of financial leverage. According to various theories such as signaling theory, information asymmetry, dynamic equilibrium theory, etc., companies that have higher transaction costs move to their target lever at a lower speed, or so-called lever adjustment speed. According to these theories, companies that score higher in terms of CSR indicators have the possibility of financing through more leverage and using financial leverage at a lower cost. Therefore, we expect leverage adjustment to be faster in companies that meet CSR requirements.In this study, a sample of 84 companies listed on the Iranian Stock Exchange over a period of 8 years from 2011 to 2018 have been studied. Multivariate regression model based on composite data was used to analyze the data and test the hypotheses. First, the target lever was estimated using a two-stage GMM. Then, the effect of CSR on lever adjustment speed was investigated. The findings of the present study confirm the positive effect of CSR score on lever adjustment speed. In other words, CSR has an impact on financing methods, transaction costs and leverage changes, and the results of the present study support this effect. Hypothesis testing also showed that firm size, leverage level and information asymmetry can affect the CSR relationship and leverage adjustment speed.

Due to contractual demands, litigation costs and legal preferences in banks, the role of conditional conservatism is important in order to increase banking transparency. Also, in the conditions of information asymmetry and financial distress, uncertainty about the quality of loans is reduced, bank managers try to reduce agency costs by increasing the quality of information through conservative reporting and increasing the informing about banks real value. Based on this, the aim of the research is to investigate the effect of information asymmetry and financial distress on relationship between accounting conservatism and loan quality portfolio in Iran's banking system. For this purpose, the data of 15 banks accepted in the Iranian capital market between 2012 and 2020 have been used. The analysis of the results using multiple regression showed that conditional conservatism has increased the loan quality portfolio (increasing the quality of bank assets and reducing the ratio of non-current claims), and informational asymmetry and financial distress with a positive effect have modified and intensified the relationship between conditional conservatism and loan quality portfolio.

The main purpose of this study is to investigate the role of accounting comparability as an intra-organizational factor on pricing considerations of information environment issues such as information uncertainty and information asymmetry. In this study, two criteria have been used to measure information uncertainty. Based on the standard deviation of cash flows by the matched company (MF) method, the first criterion of information uncertainty on the model presented by Larson and Risatek is based. To measure the second criterion three different indicators were used, and then factor analysis method was used to convert these indicators into a single criterion. Information asymmetry is also measured based on the two indicators of accruals quality and sales gap. Also, the expected return of shareholders has been calculated based on the 5-factor model of Fama and French, for pricing these issues. For this purpose, data related to companies listed on the Tehran Stock Exchange have been extracted, for the period 1388 to 1397 and a combined regression model has been used to test the research hypotheses. The results show that the comparability of profits and cash flows leads to changes in returns due to information uncertainty and information asymmetry.Thus, investors and users of financial information in the Iranian capital market as well as standard formulators should pay special attention to the importance of comparability of financial reports as a qualitative factor among organizations; this is because it reduces the effects of information environment interference on the decision-making of users of financial information.

Present study aims to design and explain the decision-making native model for selecting venture capital investment in emerging companies. In this regard, in order to achieve this goal, based on the qualitative approach of the theme analysis, the qualitative data was conducted through interviewing experts and venture capital companies, and then the decision-making native model for selecting venture capital investment in emerging companies is designed. Subsequently, in a quantitative approach, a questionnaire was developed and completed by managers of venture capital companies. To analyze the data of the questionnaire, a confirmatory factor analysis was used. The results indicate that all themes introduced in this study include: financial features, product or service, features of market and industry, risk type, entrepreneurial experience, intellectual property rights, personal competence of entrepreneur, marketing capabilities, exit strategy, participation, responsibility and social effect, rules and regulations, innovation, personality traits of entrepreneur, investment horizon, entrepreneur’s character and information asymmetry are effective for selecting venture capital in emerging companies.

This study aimed to investigate the effects of information asymmetry and illiquidity related to cluster trading on market efficiency and examine the mediating roles of these two variables in the relationship between noise trading and market efficiency. To measure the information asymmetry, Adj PIN and illiquidity related to cluster trading obtained from PSOS models were used. Also, market return based on trade volume imbalances was utilized as the indicator of market efficiency. The sample include 146 companies, which were listed in Tehran Stock Exchange between 2014 and 2020. The results showed significant inverse effects of information asymmetry and illiquidity related to cluster trading and market return. However, the effect of illiquidity related to cluster trading on market return was stronger than that of information asymmetry. In addition, the findings showed that noise trading had direct and significant effects on information asymmetry and illiquidity related to cluster trading. Thus, the relationship between noisy trading and market return through information asymmetry and illiquidity relevant to cluster trading, as well as the mediating roles of these two variables, was confirmed.

In firms where language tone of management in risk disclosure is conservative, more verification is required to disclose good risk news and a lower standard of verification is required to disclose bad risk news. This type of risk disclosure can reduce the likelihood of negative news accumulating in these firms and decrease the stock price crash risk. Accordingly, the purpose of this research is to investigate the effect of conservative tone in risk disclosure on the stock price crash. The research period is from 2009 to 2018 and the sample number included 167 firms listed in Tehran Stock Exchange. Panel data approach and multiple linear regression were used to test the research hypotheses. The findings show that Conservatism in Risk Disclosure(CRD) reduces the stock price crash risk by requiring asymmetric verification to disclose good and bad risk news. Also, given the high information asymmetry, the role of CRD as a limiter to managers' motivation to accumulate negative news and prevent the stock price crash increases.

One of the most prominent issues in financial markets is the effect of information asymmetry. Information symmetry proved to be one of the most important requirements of efficient markets. As a result, the risk of information asymmetry and the existence of inside information is one of the most effective risks for investors. The main purpose of this study is to investigate the level of information asymmetry on the Tehran Stock Exchange and also to investigate the accuracy of estimating the trading model based on the probability of informed trading model (PIN) using different trading classification algorithms. Accordingly, after selecting 40 shares of stocks present in Tehran Stock Exchange, which have been active more than 75% of the trading days of the market and using LR and EMO algorithms in the classification of transactions, the PIN was calculated and observed that the probability of informed trading had a considerable level (on average 0.25) in the Tehran Stock Exchange, which increased by moving to smaller volume deciles. Also, using the microstructure simulation method, it was observed that any deviation in the correct classification of trades affects the probability of informed trading and, as a result, can significantly affect the accuracy of the supervision system.

This study tries to develop a pattern for identifying effectual factors that influence underpricing the initial share offering of companies to the public. In this study, after selecting the appropriate explanatory variables, to achieve the research goal, the systematic elimination sampling method is considered to select 84 companies among all listed companies at the Tehran Stock Exchange (TSE) and 54 companies among all listed companies at Over the Counter (OTC) from 2003 to 2017. So, to test research hypotheses, the Partial Least Square approach in three sections is used: measurement model fit, structural model fit, and goodness of fit. Results show that information asymmetry, corporate governance, conservatism, audit quality, financial ratios, Continuity of activity, environmental uncertainty, and management overconfidence have a significant effect on underpricing of initial public offerings. Moreover, the findings confirm that the investor’s sentiment and Macroeconomic variables have no significant impact on underpricing phenomenon.

In a complete market in which information asymmetry does not exist between managers and external investors, firms can optimally invest in profitable projects. However, when information asymmetry exists, firms may be confronted to face financing constraints and cash surplus which prevent them from undertaking profitable projects, resulting in an under and over investment. Therefore, in order to achieve an optimal investment efficiency model and detection of over and under investment, the empirical test of investment efficiency models examined in Tehran Stock Exchange. In this research, different models of investment efficiency extract and examined from different economic environments and compared with the native model presented, in order to explain their explanatory power. For this purpose, the origin and economic implications of investment efficiency are used to validate the models. A model is convenient when that consistent with financial and accounting theories. The financial reporting quality, free cash flow, financial constraints, economic value added, and firm value are issues that are tested in relation to investment efficiency models. For this purpose, 180 companies are used for the period of 2007-2017. The findings showed that free cash flows and financial constraints has a positive effect on over and under investment. The findings also suggested that the investment efficiency was positively affected by the economic value added and firm value, but this effect was not confirmed through all investment efficiency models. The results showed that the test of all hypotheses was confirmed based on native model of investment efficiency.