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 natural gas fueling company Clean Energy Fuels Corp (CLNE 6.15%) dropped 14% today after reporting earnings.

So what: Fourth-quarter revenue was down 14.2%, to $85 million, and was short of the $92.6 million that analysts expected. The company also reported a non-GAAP loss of $23.8 million, or $0.25 per share, $0.05 worse than estimates. 

Now what: This is supposed to be a high-growth story in natural gas fuel, but even gallons delivered grew an uninspiring 13% last quarter. We keep waiting for significant growth in this industry but, so far, it's been a lot of hype and not a lot of growth. Until adoption picks up and Clean Energy Fuels can make a profit, I'm going to steer clear of this stock.