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: On a miserable day for the markets, Regeneron Pharmaceuticals (Nasdaq: REGN) is defying the downturn today with a tidy 9% gain (as of this writing). It could have done even better but for the negative sentiment; earlier today the shares were up as much as 11%.

So what: According to a just-released Food and Drug Administration report, the company's new VEGF Trap-Eye drug, for treatment of "wet age-related macular degeneration," a leading cause of blindness, is just as good as Roche's Lucentis, which is already on the market.

Now what: "Just as good?" It sounds like the FDA is damning Regeneron with faint praise, but the key takeaway here is that the FDA looks inclined to approve the drug for sale. If it does that, analysts think Regeneron could steal market share from Roche, inasmuch as Trap-Eye can be administered as infrequently as once every two months, versus the once-a-month regimen for Lucentis.

With a $1.5 billion market at stake (triple the size of Regeneron's current revenue stream), that's better than a stick in the eye.

Can Regeneron parlay this news into an actual profit? Add it to your Watchlist and find out.

Fool contributor Rich Smith does not own (or short) either company named above. The Motley Fool has a disclosure policy. Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.