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 Alnylam Pharmaceuticals (Nasdaq: ALNY) are dipping 10% today following the release of the company's fourth-quarter earnings results.

So what: As with most biotech companies, today's story has very little to do with the fact that Alnylam met Wall Street's estimates with a loss of $0.33 -- but has everything to do with its cash burn rate. In fiscal 2011, Alnylam burned through $89 million in cash. Its fiscal 2012 forecast anticipates that the company will end the year with "greater than $180 million at December 31, 2012." This implies a cash burn rate of up to $80 million more.

Now what: Alnylam has already had a huge run, doubling in price since late November. The RNAi therapeutics company currently has three experimental therapies in phase 1 clinical trials and one in phase 2 trials. Partnered with Cubist Pharmaceuticals (Nasdaq: CBST) to license the drug worldwide (excluding Asia), ALN-RSV01 is aimed at treating RSV infection in adults. With no other trials currently past phase 1, it's this RSV drug that holds all of the promise for Alnylam. Personally, I see downside potential for the stock given the rapid cash burn rate and the fact that a marketable drug still appears to be years away.

Craving more input? Start by adding Alnylam Pharmaceuticals to your free and personalized watchlist so you can keep up on the latest news with the company.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.