Just read the article until the end.

> Yee, though, says Gilead isn't filling a hole left from its declining HCV unit. It's merely coming down off a "massive bolus of hundreds of thousands of people who came in during the first two years."

> "The drug is still set to do $8 billion in 2017 and is one of the largest drugs in the world. Not exactly a hole," he said.

The Gilead stock is worth 4x today what it was worth in 2012, before they had the cure. It is better than the average "big-pharma" (ex: Pfizer). The stock plateaued because they couldn't follow up, but before you look at the dip, you should look at the massive raise before it.

Wall Street dinged them because Gilead is a one trick pony and the street overestimated revenue, not because Gilead cured HCV rather than just treating it.

Additionally, if their drug didn’t work as well they wouldn’t have gotten away with charging 100k for a course and wouldn’t have made 40B+ in revenue.