ENTA has never reached the highest (20%) royalty tier, but they did reach the second-highest (17%) tier in 2018 and 2019.
As shown in the schedule in #msg-142808661, reaching the highest royalty tier would require ABBV's HCV sales in a given calendar year to exceed $5B ($2.5B/0.50), which is not gonna happen.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”