The Relationship between Quality of the External Auditor and Bid-Ask Spread in Tehran Stock Exchange

The purpose of this research in to examine the relationship between Bid-ask spread and quality of the external audit in the Iran capital market. To achieve this goal we have considered two hypothesis including audit big firm and audit firm tenure and choose 108 companies between accepted companies in Tehran stock exchange for four years (1384 to 1387). The method used in this research for testing the hypothesis is panel data.The findings of the research show that bid - ask spread have a meaningless relation with audit big firms and audit firm tenure have negative relation and they are meaningful.