Fig. 1.

Cumulative stock returns around first day of clinical trial phases.

The figure plots the average cumulative returns of all 50 stock markets over the [-5, +5] event window around the start of clinical trial phases of all 83 vaccine candidates. The first day of each clinical trial phase is marked as “day + 1” in the event window. The cumulative return is calculated for each event window, and then averaged across all country indices and clinical trials. The 95% confidence intervals are also reported with vertical black lines. The dotted line indicates the time cutoff before and after the start of clinical trial phase.