فصلنامه بورس اوراق بهادار
پیاپی 55 (پاییز 1400)

This research is an attempt to introduce a desirable pattern for Dynamic Modeling of the Estimated Optimal Ratio of Gold Coin Risk Coverage. Given the unique nature of Iran in producing and supplying saffron and weakness in the commercial sector of this product, it was necessary to supply this product through the Iranian Stock Exchange. Following the presentation of the Saffron Deposit Certificate in the Iranian Commodity Exchange in 2017, the futures contracts for saffron in the Iranian Commodity Exchange were defined in 2018. On the other hand, the gold coin futures market was halted in 2018 due to the volatility of the gold coin market. Therefore, considering the importance of estimating the risk coverage in financial markets, in this study, we modeled the estimation of the optimal ratio of daily gold coin risk with respect to the future contracts of saffron from May 22, 2018 to October 22, 2019, through the Coppola functions and wavelet analysis. And the combination of these two models is discussed. The results of the study show that the saffron futures market is able to estimate the risk coefficient of gold coin cash market risk and that investors can use this market to cover their risk. In addition, in terms of structural dependence on the basis of the Coppola functions and wavelet decomposition, it results in an optimal estimation of the coverage over the medium and long time periods.

 The purpose of this study was to investigate and explain the factors affecting corporate investment efficiency, to investigate the role of firm characteristics in the relationship between disclosure of risk information in annual reports and investment efficiency of listed companies. The Tehran Stock Exchange was conducted in the period of 2008-2017. In this study, company size, profitability, and company growth were used as characteristics of the company. The results showed that there is a significant relationship between disclosure of risk information in annual reports and investment efficiency. There is also a significant relationship between company characteristics with disclosure of risk information in annual reports and between company characteristics and investment efficiency. Multiple regression method, Baron and Kenny method were used to investigate the mediating role of firm characteristics on the relationship between risk information disclosure in annual reports and investment efficiency. The results of the hypotheses test showed that firm size and profitability play a partial mediator role in the relationship between disclosure of risk information in annual reports and investment efficiency and variables of disclosure of risk information in annual reports, company size and profitability Can predict the efficiency of investment. The results also show that growth variables do not have a mediating role in the relationship between disclosure of risk information in annual reports on investment efficiency.

The objective of this paper is to offers a Meta - analysis of the relationship between Investor Sentiment and Stock Returns . Although it is taken for granted in the scientific research area that sentiment do influence stock returns , they have produced contradictory and inconsistent results . This paper applies meta -analysis,which is considered among quantitative statistic metods , in order to integrate the existing body of research and identify the moderators of the relationship between Investor Sentiment and Stock Return . The results of studies conducted about this relationship indicate that these studies are heterogeneous .The recorded studies consisting of Master and Ph.d. theses as well as recognized national and international papers have been selected as research populatiob.Out of these 134 research 72 cases were found qualified and suitable having the condition for studying meta - analysis . The final results showed a significant relationship between Investor Sentiment and Stock Return .

The term business model (BM) is one of the topics that has recently been addressed in the area of accounting literature. The weaknesses in current reporting, including failure to meet social responsibility goals, have led the researcher to identify the components of the financial reporting based on the theoretical foundations associated with the concept of business model (BM). Since the present study is a qualitative research, in the first step in order to collect qualitative data, a framework for semi-structured queries with experts was developed. Subsequently, 23 well-known academic and executive experts in the field of financial reporting and business were selected through purposeful sampling (snowball). The transcribed interviews were coded in the second phase using inductive thematic analysis. In inductive theme analysis, patterns emerge during the analysis by placing open source or sub-themes together in one main theme. In summary, in the current study out of a total of 350 open source codes and 24 sub-themes, 6 main themes were identified as transparency and narrative, social accountability, users, key drivers, justice and fairness in reporting and presentation and disclosure. Financial reporting and information disclosure are important management tools for effectively transferring information to stakeholders. Reliable and timely financial reporting enables individuals to accurately assess their future prospects. Therefore, by re-engineering the financial statements, six key components of financial reporting, inspired by the business model (BM) approach, can be a major step in re-engineering financial statements to improve the information content of financial statements.

The Black-Scholes pricing theory is one of the most important ways of valuating transaction options. This equation is used to pricing a variety of European options. In this paper, a new and different method was developed to prove and improve the Black-Scholes equation by focusing on the Black-Scholes main Schrödinger equation and solving this equation using the Nikkeuro-Ovaryov method. In the following, while investigating the possibility of improving the Black-Scholes equation with this method, a new equation for the pricing of transaction options was presented and tested. Increasing the accuracy of pricing arbitrary deals by using the equation provided, especially for high-value trades, checking logical solution in a new way, comparing output with numerical solution and innovating. Final formula. Option based on Lagrange polynomial functions, the goals of doing research are present. The results showed a different positive probability for the Black-Scholes equation by solving the differential equation by the method Nikkirovo-Ovaryov is feasible and at 95% confidence level, there is no significant difference between the price of the two main black-hole groups and the new model. In order to compare the output of the new model with the Black Sholes main model, information from the 50 Saffron Deal options in Iran's Overseas Branch was limited to the 1395 to 1398 period and the Mann-Whitney independent nonparametric group was used to compare.

Inappropriate response of executives to investor sentiment can lead to litigation and misallocation of funds, for this reason, companies set up conservative accounting in response to investor sentiment. This paper investigates the association between investor sentiment and accounting conservatism. For this purpose, the data of 119 companies listed in Tehran Stock Exchange for the period of 2008 to 2017 were extracted and combined data regression model was used to test the research hypotheses. The results show that managers identify economic losses in a timely manner during periods with high investor sentiment. In addition, the relationship between sentiment and conservatism is stronger for companies whose values tend to be high. We also find that the relationship between sentiment and conservatism is higher for companies with higher litigation risk. Overall, our results suggest that companies report earnings more conservatively in response to higher investor sentiment in order to mitigate potential litigation costs. These findings have implications for regulators and standard setters who have deemphasized accounting conservatism in recent years.

Given the important role of financial derivatives in the world economy and experience of the necessity of applying high quality and accepted financial reporting standards especially financial instruments standards, the purpose of this study was to identify information disclosure challenges related to derivative instruments in Iranian reporting environment And within the framework of International Financial Reporting Standards. Method This study identifies and presents the challenges of disclosing derivative securities and hedge accounting information in accordance with IFRS 7 and IFRS 9, using the qualitative content analysis method of analyzing the data obtained from interviews with 4 experts of auditing, accounting and capital markets of Iran.The identified challenges in identifying, measuring and disclosing derivative tools lead to challenging practice requirements. The findings show that the complexity and difficulty of implementing disclosure requirements in practice, along with a lack of incentives to comply with disclosure requirements and lack of transparency in financial reporting, along with the weakness of executive reporting requirements in the Iranian reporting environment, will have negative impact on effectiveness of standard and derivative instruments reporting. resulting in a lack of sufficient, comparable, useful and reliable information in this area.Standard setters and professional accounting and auditing communities should be aware of challenges of accounting and reporting of derivative securities and prepare suitable infrastructures for financial reporting of these securities in Iranian financial reporting environment.

The Lack of corporate governance mechanisms, increasing shareholder interests, and improving performance make it difficult for companies. Timely dissemination of information reduces information asymmetry, rumors and information leakage in the market. The purpose of this study is to improve effective decision making for investors and, on the other hand, for corporate executives to achieve positive results and ultimately improve the performance of their companies. In this study, the data of 152 listed companies in Tehran Stock Exchange were studied. This information was collected by the new approach software and analyzed by multiple linear regression using Eviews9 software. The results showed that the CEO's duality had an adverse effect on the timeliness of financial reporting and the size and independence of the Audit Committee had a direct effect on the timeliness of financial reporting, The auditor's expertise also has a significant effect on the relationship between the size and independence of the Audit Committee on the timeliness of financial reporting.

This study investigates the behavioral factors of legal investors in Tehran Securities and Exchange Organization. Its purpose is to assist Managers of Securities and Exchange companies in making sound financial decisions by informing them of these behavioral factors. If managers gain a better understanding of themselves and their beliefs in the financial arena and try to refine destructive financial beliefs, they can improve the financial performance of the company and feel more desirable in addition to achieving long-term financial goals.Therefore, in this study, managers' monetary beliefs as one of the most important aspects of influencing financial behavior and financial performance of a company in a comprehensive model have been investigated and evaluated. This research was conducted by surveying and distributing questionnaires among 70 executives of Securities and Exchange companies in 1397. Based on the results of structural equations, the findings show that there is a significant relationship between managers' monetary beliefs (Psychology of Money) and their financial decisions and firm's financial performance. Managers who are money worship, also have better financial performance than other monetary personalities.

One of the main factors in promoting the financial and economic efficiency of the firm is corporate governance, which includes a set of relationships between the company's management, board of directors, shareholders and other stakeholders. Also, the importance of the company's financial management decisions in the optimal allocation of resources and the role of corporate governance in improving it, shows the necessity of the subject. Therefore, the amount and direction of the impact of various aspects of corporate governance, including ownership and independence of the board, the share of institutional investors and duality of CEOs using the financial data of companies on the Tehran Stock Exchange during the period 1393-97. For this purpose, the components of corporate governance are considered as predictor variables and the variables of leverage, size and life of the company are considered as control variables. The results show that board share ownership has a significant impact on investment decisions and company performance. Also, the independence of the board of directors as one of the dimensions of corporate governance is significantly related to the three components of financial management decisions.

In the conceptual framework of financial accounting, which serves the purposes of financial reporting, special attention has been paid to cash flow. The purpose of this study is a new understanding of cash flow behavior and the creation of a new experimental model. This research is applied in terms of purpose and quantitative in terms of implementation. The statistical population of the present study is the annual cash balance of 48 specific bank branches (due to the confidentiality of information, it is not mentioned). Two hypotheses have been considered in this research: 1) Cash balances has a Stochastic property; 2) The Geometric Brownie model is better than the Arithmetic Brownie, Vasicek, and Modified Square Root models. The results of the test have been confirmed to be random. Also, by comparing the four models using MSE, RMSE and MAE tests, the best estimation model has been selected and the comparison results of the models have confirmed the Geometric Brownie inclination model as a more efficient model.