Modeling the impacts of OPEC oil price fluctuations on the Iranian investors sentiments- nonlinear and time-varying parameter

In classical finance, investors sentiment play no role in expected returns and stock prices, but behavioral finance believes that investors decisions are influenced by their sentiment.In oil-producing countries, including Iran, the news of OPEC oil price fluctuations affects investors sentiments . we used the monthly data for the period of research 2008 to 2021.The research method of this article is an application uses the nonlinear and time varying parameter models.The results show that OPEC oil price fluctuations on investors' investment follow nonlinear process .Change in a standard deviation in OPEC oil price fluctuations over time has a U-shaped effect on investor sentiment (moving on a horizontal axis).Changes in standard deviation in OPEC oil price fluctuations in each period (moving on the transverse axis), at the beginning of the second period have a strong negative effect and in the middle and end of period have a small negative effect on investors sentiments.