Investigating return and volatility spillovers among selected industries of the Iranian stock market: TVP-VAR Extended Joint and DCC-GARCH approaches

Understanding the transmission of shocks and fluctuations among financial assets is crucial for effective risk management by investors. This study analyzes the dynamics of return spillovers and turbulence propagation across 15 industries in the Tehran Stock Exchange from October 12, 2009, to May 15, 2024. Employing the extended joint vector autoregression framework with time-varying parameters (TVP-VAR Extended Joint), we examine return spillovers, while turbulence spillovers are investigated using the dynamic conditional correlation (DCC-GARCH) approach. Our findings reveal several insights: Firstly, return shocks and turbulence in the network exhibit distinct dynamics. Secondly, the systemic risk resulting from turbulence transmission indicates tighter and more intricate interconnections among industries compared to return transmission. Thirdly, apart from the dominant investment industry, which serves as a major transmitter of shocks and fluctuations in both analyses, the pharmaceutical, construction, and food industries also emerge as significant net transmitters. Finally, the study confirms a strong dynamic synergistic relationship between basic metals and metal minerals throughout the study period.