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 FuelCell Energy Inc. (FCEL -0.21%) dropped 20% today after the company released disappointing earnings.

So what: Fiscal fourth quarter revenue was up 55.8% to $55.2 million, which was above the $44.8 million estimate from Wall Street. But investors are more concerned about a $0.05 per share loss, which was two cents worse than estimates and puts expected earnings improvement next year in question. 

Now what: The loss may have been disappointing, but there was a lot of progress in the quarter. Backlog increased to $355.4 million from $318.9 million a year ago and there was the 56% jump in revenue. I think the reaction is harsh given the quarter's progress and wouldn't be worried about missing the earning guess of just two analysts. In short, I see this as a buying opportunity today.