Much of what I am looking at is in the red today. Further, some Enta (-6.3%) similar small caps are down; AGIO -5.5%. PRDS -13.8%, and ABUS -10.7%. A sea of red.
It seems to me that this December selling is quite common for Enanta. I've also seen large gains also in the New Years period.
FWIW I at one time held MDGL but got impatient and years earlier sold the few shares I had; It was a win in a way cause they were no longer a distraction. The Enanta covid program OTOH has a relatively near time frame readout that very well could distinguish itself from other antivirals.