Do retail traders destabilize financial markets? An investigation surrounding the COVID-19 pandemic
研究了COVID-19大流行期间散户交易对股市波动的影响，发现散户交易在危机时期（如大流行和2008-09年金融危机）会加剧波动，且影响比平时更强。
Existing research suggests that retail trading is associated with volatility in financial markets. To extend the literature, we study the dynamic effects of retail trading on volatility during the COVID-19 pandemic. Using marketable retail trades identified from the Boehmer et al. (2021) algorithm and novel empirical methods discussed in Jordá (2005), we document a negative, persistent impact of retail trading on the stability of stock prices that is particularly stronger during the pandemic than during the pre-pandemic period. These results highlight how periods of crises - like the pandemic - affect the destabilizing influence of retail trading. To provide additional evidence, we replicate our empirical exercise during the 2008-09 financial crisis. Consistent with the COVID-19 period, we again find that retail trading leads to more volatility during the financial crisis vis-á-vis the pre-crisis period. These results again support the idea that periods of crises strengthen the link between retail trading and volatility.