What happened 

Shares of Clean Energy Fuels Corp (NASDAQ:CLNE) fell 11.5% during February, according to data provided by S&P Global Market Intelligence, as investors continued to lose hope in the company. Even a new partnership couldn't save the stock last month.

So what

There wasn't one big driver of Clean Energy Fuels' fall in February, which is concerning ahead of earnings on March 13 after the market closes. The company did announce an exclusive partnership with the Harbor Trucking Association (HTA), a "leading voice" in West Coast ports. But there weren't many details and no assurance of future cash flow from the agreement, so it did little to move the needle.

A semi-truck driving down the highway.

Image source: Getty Images.

The more time goes by, the more we hear about Tesla (NASDAQ:TSLA) and others pushing further into the trucking market. Tesla is already testing its Semi to move goods from the Gigafactory to its California manufacturing plant. If electric drivetrains become viable for long-haul trucking, the natural gas fuel business will be dead.

Now what

It's hard to see how Clean Energy Fuels can have a bright future given the progress of electric vehicles over the past five years. On top of that, the company isn't making money and revenue has been declining the past two years. I don't see the outlook turning around and I think the decline in Clean Energy Fuels' stock in 2018 is just the beginning.