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 Clean Energy Fuels (Nasdaq: CLNE) -- the corporation, not the concept -- roared to morning gains as high as 17.1% today amid muscular trading volume.

So what: The producer of vehicle-grade natural gas fuels is on the rise because gas explorer Chesapeake Energy (NYSE: CHK) just promised to buy $150 million of Clean Energy bonds over the next three years. The announcement was followed by an upgrade from Northland Securities.

Now what: Proceeds from the bond sales will let Clean Energy build about 150 refueling stations at strategically chosen truck stops across America, moving natural-gas vehicles closer to the mainstream. This builds on a recent deal to provide natural-gas fuels at 48 UPS (NYSE: UPS) depots as well as a manufacturing deal between Westport Innovations (Nasdaq: WPRT) and General Motors (NYSE: GM) that will put more compatible trucks on the road. Clean Energy might be onto something big here when you put all these moves together.

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