Why hold a CC at 4pm after hours when news is out

Why hold a CC at 4pm after hours when news is out already unless something else we are not aware of? So if SP is dropping 50 % on open why sell now when COVID unbinding m2m is this week and then it seems we get a look at the Severe Phaseiii next week due to possible deaths in the Placebo group and or both? I would hope just the placebo group. This week and next and can still catapult the SP in the direction we anticipate.