ENTA—…it's probably a big buyer and/or short covering.
I don’t consider that an independent explanation because it doesn’t say anything about the impetus for the buying and/or short covering.
You'd think if it was Harvoni related, ABBV would also be up to some degree.
Maybe; however, ABBV has a lot of things going on aside from HCV, such as reevaluation of the SHPG acquisition in light of the new US Treasury regs on tax inversions.