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 Regeneron Pharmaceuticals (Nasdaq: REGN) jumped 13% today after the company said sales of Eylea were strong in the fourth quarter.

So what: Sales of Eylea, which launched on Nov. 21, were $24 million to $25 million in the fourth quarter, according to CEO Leonard Schleifer. He said he expects sales of Eylea in 2012 to be $140 million to $160 million.

Now what: The expected results are much higher than analysts had expected, causing the jump in shares today. Robert W. Baird analyst Christopher Raymond upgraded the stock to outperform as a result of the positive news. The results are no doubt positive, but to put this into perspective, the company's market cap is up $748 million today on the news, so I'm not jumping for joy at the stock's higher price today.

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