Exploring the causal links between investor sentiment and financial instability: A dynamic macro-financial analysis

Investor sentiment may not only influence financial instability, it may also be shaped by it. Moreover, such causal links may differ over time, in crisis and non-crisis periods. This is a groundbreaking paper that tests these two hypotheses from a macro-financial perspective using the bootstrap rolling window sub-sample Granger causality approach to look at the case of the U.S. financial market between January 1990 and January 2021. We find that bullish sentiment can reduce financial instability as it promotes financial market entry and then liquidity during non-crisis periods, while higher financial instability is associated with less bullish sentiment leading to a shift to crisis periods. The results also reveal a positive (negative) effect of bearish (bullish) investor sentiment on financial instability during crisis periods, including the 2007–2008 financial crisis, the 2010 flash crash, the 2015–2016 Chinese stock market turbulence, and the February 2020 stock market crash. Finally, the study highlights the important role of the “betting against beta” strategy in the U.S. financial market, showing a negative effect of financial instability on bearish investor sentiment during several pre- and post-crisis periods.