The influence of extreme events such as Brexit and Covid-19 on equity markets

In this article first, we show that the result that the PIIGS group had the largest negative unadjusted and abnormal returns on the day following the Brexit Referendum is robust to taking into account jointly other extreme events such as the Covid-19. Second, we provide evidence that the impact of the declaration of Covid-19 to be a global pandemic by the WHO – when global markets fell by nearly 15% – had a total different reaction in the financial markets to the one following the Brexit Referendum, impacting more negatively in countries where quarantine lockdowns were announced that day (i.e. Austria, Belgium, Brazil, Canada, Italy and Spain), independently on their debt-to GDP ratio. We also show that the day after Covid-19 was declared as a global pandemic, China and Japan (countries that already implemented lockdowns in the previous months) were the only analyzed countries that did not experience any evidence of abnormal returns in their financial markets. Moreover, during the three following days, the US was the only analyzed country showing no evidence of negative abnormal returns due to the declaration of the national emergency. These results suggest that government policies must take into account and monitor specially health-related news at global level, since they can have enormous impacts on portfolio allocations on stock markets, in order to take more informed decisions.