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: Alexza Pharmaceuticals (Nasdaq: ALXA) shares fell 52% today after the Food and Drug Administration did not clear the company's new drug, AZ-004.

So what: This is disheartening news for Alexza shareholders with hopes for AZ-004, which would treat patients with schizophrenia or bipolar disorder. This doesn't spell the end for the drug because the company expects to meet with the FDA soon, but it at the very least hurts any planned launch timeline.

Now what: This puts Alexza in a tough spot not only with the drug but financially as well. The company had $14.2 million in cash at the end of the latest quarter and burned through $8.3 million in cash during the quarter. Even if AZ-004 achieves a positive outcome in coming quarters, shares may be diluted by further stock offerings. I would be cautious on Alexza until we hear positive news.