Document Type : Research Paper
Authors
1 PhD in Accounting, University of Mazandaran
2 Professor of Accounting in the Department of Accounting at the Mazandaran university
Abstract
1. Introduction
Block trading, as one of the significant events in capital markets, has always attracted the attention of financial analysts due to the large volume of shares transferred and its potential to influence prices and liquidity. These transactions can have consequences for market efficiency and information transparency by transferring information and altering the ownership structure of companies. On the other hand, media coverage plays a moderating role in this process by reducing information asymmetry and increasing investor awareness. Accordingly, the present study examines the effect of block trading on information asymmetry, emphasizing the moderating role of media coverage in the Tehran Stock Exchange. The main objective of this research is to analyze the precise effect of block trading on information asymmetry as one of the outcomes of such transactions and to identify the role of media coverage as a moderating factor. By providing a deeper understanding of how block trading affects the market, this research can assist investors and financial analysts in making more informed decisions. Furthermore, by examining the role of media coverage, it seeks to identify and analyze how public information influences market behavior and investor reactions to block trades. From a theoretical perspective, this study can contribute to the development of existing theories in finance and investor behavior, creating new frameworks for analyzing financial markets. In other words, this research can help establish a new discourse on the relationship between media, large transactions, and market behavior, paving the way for future studies in this field.
2. Methodology
In terms of purpose, the present study falls under applied research, as its results can serve as a basis for decision-making by managers, policymakers, and capital market investors. Regarding data type and execution process, this research adopts a quantitative approach and is ex-post-facto in nature. The research data include information from all companies listed on the Tehran Stock Exchange between 2014 and 2024 that conducted at least one block trade. After applying systematic elimination, 100 companies with a total of 19,227 block trades were selected as the final sample. Data analysis was performed using descriptive and inferential statistics and the Generalized Method of Moments (GMM). The tools used include Raah-Avard Novin and Excel software for extracting and calculating variables, and Stata for hypothesis testing and result analysis. The validity of the GMM method was examined using Arellano & Bond (1991) tests, including the Sargan test for instruments and the m2 test for second-order serial correlation.
3. Findings
This research investigated the effect of block trading on information asymmetry in the Tehran Stock Exchange, considering the moderating role of media coverage. The main findings indicate that the number of block trades and the ratio of block trading volume have a positive and significant impact on information asymmetry. In other words, block trading is associated with increased information asymmetry. Additionally, media coverage negatively moderates the relationship between block trading and information asymmetry; that is, the positive effect of block trading on information asymmetry is weakened in companies with more extensive media coverage. This means that active news coverage, by reducing information asymmetry, diminishes the positive impact of block trading on information asymmetry. The reason for this is attributed to the inefficient structure of Iran's capital market and the need for media coverage to enhance transparency and better reflect company-specific information in stock prices.
4. Conclusion
Regarding the level of block trading in Iran and its trends, it can generally be stated that Iran's stock market, unlike other countries, faces challenges due to issues such as inefficiency, high ownership concentration, and lack of transparency in information dissemination. The untimely announcement of positive and negative news and investors' lack of trust in available information prevent the informational content of block trades from being adequately reflected in stock prices. This situation increases access to private information for informed investors, thereby intensifying information asymmetry between informed and uninformed investors. Furthermore, the synergy between normal and block markets helps reduce liquidity shocks and the risk of these stocks. Companies with active block markets have higher liquidity, and their trading volume is greater compared to the normal market. Improved liquidity following block trades contributes to increased market efficiency. In the second part of the research, the conclusion indicates that media coverage has a positive effect on the relationship between block trading and information asymmetry. Companies that have active media coverage and promptly disclose information and objectives of block trades are able to attract new buyers, thereby reducing information asymmetry. The final conclusion is based on the principle that information transparency mechanisms, such as media coverage, play a vital role in optimizing the benefits of block trading for Iran's capital market.
Keywords
- Block trading
- information asymmetry
- media coverage
- Information Transparency
- Capital Market Efficiency
Main Subjects
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