Investigating the effect of major shareholders' ownership on stock price concurrence with emphasis on the quality of information disclosure of firms listed on the Tehran Stock Exchange

The main purpose of the current research is to investigate the effect of major shareholders' ownership on stock price concurrence with emphasis on the quality of information disclosure of firms listed on the Tehran Stock Exchange. The current research is a part of applied research in terms of its purpose and a part of review research in terms of its nature. In terms of the type of argument, the pamphlet is deductive-inductive research, and in terms of the time dimension, the pamphlet is retrospective research. In terms of the duration of the research, it is part of the combined method. The statistical population of the current research is the companies listed to the Tehran Stock Exchange, after removing the restrictions, 110 companies were selected as a statistical sample. The period under investigation is between 2012 and 2020. In some cases, it has happened that investors and stock market activists combine information to gain profit and increase efficiency, or conduct transactions by distributing information to each other. Now, in the meantime, the simultaneous discussion of stock prices also shows itself because the prices that exchange hands between the stock market participants and carry out transactions reflect the progress or retreat of the market. The results of the first hypothesis test indicate that the ownership of major shareholders has an inverse and significant effect on the simultaneity of stock prices. In other words, with the increase in the ownership of the major shareholders, the synchronicity of the stock price decreases, and on the contrary, with the decrease in the ownership of the major shareholders, the synchronicity of the stock price increases. Also, the results of the second hypothesis test indicate that the quality of information disclosure has an effect on the relationship between the ownership of major shareholders and the simultaneity of stock prices.