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: Shares of biotech Incyte (Nasdaq: INCY) surged as high as 17% on Wednesday after The U.S. Food and Drug Administration approved its Jakafi pill, a drug designed to treat the rare bone marrow disease myelofibrosis.  

So what: "The availability of Jakafi is a significant medical advancement for people living with myelofibrosis, a debilitating disease," said Incyte CEO Paul Friedman. However, only about 3,500 people in the U.S. are diagnosed with myelofibrosis every year, so today's late-day sell-off -- Incyte shares are now up only 4% -- might be a reflection of that limited market potential. 

Now what: Incyte intends to launch Jakafi with partner Novartis (NYSE: NVS) as soon as next week. Of course, when you couple the stock's drubbing over the past few months with today's not-so-explosive reaction, I'd be a little cautious about jumping for joy. After all, with a lofty price-to-sales multiple of 10.5, much of the good news might already be baked into the stock.

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