In Allergan, the issue is its valuation, which is quite excessive, versus the pure sex appeal of Botox, their anti wrinkle (and possibly other things: Migraines, Cerebral Palsy, Obesity) injectable drug. Botox's competitor is Restinyl (sp?) which most doctors say is better than botox. Other than botox you have a small pipeline and legacy business that has a large presence in opthalmic indications.
As an accountant I can say that I screen for "cashless growth" and thats how I found it.
Occasionally, if you want a pair to offset the short exposure, you can use ACL (Alcon) as a long.