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 biotechnology company Optimer Pharmaceuticals (NASDAQ: OPTR) climbed 13% today after preliminary 2012 sales for its diarrhea drug Dificid impressed Wall Street.

So what: The stock has slumped in recent months on concerns over sluggish Dificid sales, but today's preliminary 2012 numbers -- sales in the U.S. and Canada totaling $74.4 million versus $21.3 million in the year-ago period -- suggest that management's turnaround initiatives are taking hold. In October, Optimer announced a 25% price cut on Dificid to help boost its adoption rate, and it looks like hospitals are indeed biting.

Now what: Expect the positive sales momentum to continue. "We believe the early response to our new strategy is very encouraging," President and CEO Pedro Lichtinger said in a statement. "We are particularly encouraged by increased DIFICID use in hospitals that our sales force is targeting, and by the number of hospitals that are initiating a review of DIFICID's formulary position."

So while Optimer remains too speculative for this Fool, more aggressive growth seekers might want to take a closer look.