Stock prices drop on bad NEWS.

The end of Humira patents in early 2023 is not news at all.

It's been well known and discussed for years, so the effects have been baked into analysts' earnings expectations for years.

The company has a good product line-up and pipeline as their management has been forewarned that Humira won't go on forever.

On the contrary, I read that AbbVie might actually cling on to part of their Humira business with longer running patents indirectly connected with the drug.

Disclaimer: I bought the stock after it was beaten down on announcing the Allergan takeover, so I'm long ABBV. It's done very well since then - and if I'd been worried about the long known impending fizzling of Humira profits, I would have sold.

Edit: typo