Investor sentiment and dynamic connectedness in European markets: insights from the covid-19 and Russia-Ukraine conflict

The primary objective of this study is to explore the dynamic relationships between equity returns or volatility and sentiment factors in European markets during both the periods preceding the COVID-19 pandemic, the COVID-19 itself, and the Russia-Ukraine war. We achieve this by applying the network methodology initially introduced by Diebold & Yilmaz (2014), along with its extensions based on realized measures and generalized forecast error variance decomposition, as proposed by Baruník & Křehlík (2018) and Chatziantoniou et al. (2023). Additionally, we investigate how the global sentiment factor influences the overall connectedness index by employing a quantile-on-quantile approach, following the methods outlined by Sim & Zhou (2015) and Bouri et al. (2022). To conduct our analysis, we utilize daily-frequency data encompassing the period from January 1, 2011, to December 31, 2023, covering the entirety of the COVID-19 pandemic in 2020 and the Russia-Ukraine conflict in 2022 across six European stock indices. Our primary discovery is the interconnectedness of both returns and sentiment. Furthermore, our results indicate that during the COVID-19 and Russia-Ukraine war, there is a notable increase in volatility spillovers among the analyzed stock indices, driven by the heightened interconnectedness between stock market returns.