Investigating the Effect of Banks' Speculative Behavior on the Stock Price Index during the Period (1392-1398)

The stock price index is the overall result of capital market activity in the real sector of the economy; but its sharp decrease or increase, unrelated to production, is due to speculative performance. The purpose of this article is to investigate the impact of banks' commercialization, including commercial, specialized, privatized and private, on the stock price index. Estimates have been made using a data panel model during the period 1392 to 1398. Banks' behavior has been examined using the variables of deposit surplus, banks' debt to the central bank and non-current facilities. The results show that the speculative performance of non-governmental banks on the stock market index is much higher than state-owned banks. Regarding the effect of model variables, the elasticity of the stock price index to surplus deposits in privatized banks ranked first, in private banks ranked second, commercial banks ranked third and specialized banks ranked last. The elasticity of the stock index to the debt of banks to the central bank was significant only for the debt of private banks, and the elasticity of the index in other banking groups to the central bank was not significant. The elasticity of the stock index to non-current facilities in specialized banks was ranked first. The amount of this elasticity in private, privatized and commercial banks was almost equal.