What happened

What goes up sometimes comes back down for no good reason.

Two days ago, natural gas refueling company Clean Energy Fuels (CLNE -0.87%) exploded higher on news that it had just signed a five-year contract with the Los Angeles County Metropolitan Transportation Authority (L.A. Metro) to supply 47.5 million gallons of renewable natural gas (RNG) "to fuel the nation's largest transit bus fleet."

The momentum carried into Tuesday trading, but by Wednesday, it seems Clean Energy was running on fumes, and so the shares took a breather -- down 9.1%.

Blackboard drawing of stock chart arrow going up being erased and pointing back down

Image source: Getty Images.

So what

And that's OK.

Clean Energy stock is still up 31% from its closing price at the end of last week. While investors can't be faulted for wanting it to go up just a little bit more, I'd say the stock has already been amply rewarded for its good news.

Now what

Plus, there's more than a fleeting possibility that Clean Energy stock will go up some more. After all, as Clean Energy explained on Monday, its five-year contract with L.A. Metro contains an option for the transit agency to extend the contract's duration for another three years. That's one future catalyst.

And as I mentioned on Monday, there's more good news for the company already, specifically, the fact that Amazon.com (AMZN -1.64%) just ordered 1,000 natural gas truck engines from a joint venture between Cummins (CMI -0.12%) and Westport (WPRT -3.93%). Those truck engines may not hit the roads immediately, but once they do, someone is going to have to fuel them -- and Clean Energy Fuels is the most recognizable name in this space, and the most logical company to do that.

The more the transportation industry leans into using natural gas to fuel its big delivery trucks, the better things will get for Clean Energy Fuels.