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 Keryx Biopharmaceuticals (NASDAQ:KERX), a biopharmaceutical company focused on developing therapies to treat renal disease, tumbled as much as 10% after announcing a proposed $90 million public offering of stock after the closing bell last night.

So what: According to Keryx's late-day press release, JPMorgan Chase is helping the company underwrite a $90 million proposed stock offering, which Keryx plans to use to fund the pre-launch and launch inventory of Zerenex -- its experimental chronic kidney disease (CKD) drug designed to treat hyperphosphatemia, which is currently under review by the Food and Drug Administration – as well as the development of Zerenex in pre-dialysis and for general corporate purposes. Based on Keryx's current share price as of this writing, the common share offering would add close to 6.2 million new outstanding shares, diluting existing shareholders by about 7.5%.

Now what: Given that Keryx Biopharmaceuticals was trading near a 52-week high, a share offering was practically inevitable. The money generated from this offering is going to fuel its early-stage marketing for Zerenex, as well as product build-out, which is a key step to launching its new CKD product. However, you're also witnessing the downside to clinical-stage companies in that they have a tendency to squash any rally with dilutive share offerings to ensure they have enough cash left in the bank to keep their research going. While I'd certainly say Zerenex presents a favorable efficacy profile thus far, I'm simply not convinced that Keryx is anywhere near value territory here at a $1.2 billion market cap. As such, I'm planning on personally keeping my distance from this company until well after the FDA's decision on Zerenex.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

The Motley Fool owns shares of JPMorgan Chase. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.