Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Amylin Pharmaceuticals (Nasdaq: AMLN) shares bounced 10% today on an upgrade from analysts at Leerink Swann.

So what: Amylin saw its stock drop 50% last week when regulators declined to approve Bydureon. The stock may have oversold on that news, and analysts think it still has upside even with a longer lead time on the diabetes treatment.

Now what: Bydureon still has a long road ahead and this Fool never likes buying because an analyst says so. This looks like a typical upgrade bump to me, without any solid news from the company. I'm selling the move today given the long-term uncertainty surrounding Bydureon.

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