What: Shares of natural gas refueling expert Clean Energy Fuels Corp (NASDAQ:CLNE) fell more than 12% today (October 17) after a strong rally mid-week. The thing is, the share price has been all over the map lately. Just in October, shares have moved up or down more than 5% at least five days.

CLNE Price Chart

CLNE Price data by YCharts

In short, this volatility is unsettling for many, especially since it is being driven almost entirely by speculation, and not a lot of news directly related to Clean Energy Fuels. 

So what: With the exception of an October 15 press release reporting record CNG deliveries last quarter -- sparking a 20%-plus rally over a couple of days -- there hasn't been any direct news about the company lately. Westport Innovations' announcement that it was reducing revenue forecast for the year by 25% -- Westport is a key manufacturer of natural gas engine technology -- certainly has been a big part of the sell-off, but Westport management made it clear in their revision that their ISX12 G engine for heavy trucking -- built in partnership with Cummins -- wasn't affected, and was selling well. So while the news has been mixed, there's a lot of indication that Clean Energy's business continues to grow stronger. 

Now what: Early after-hours market action was mostly positive, with the share price jumping 6% from today's close at one point, before cooling off and settling back at the closing price. The point?

It's probably heavy speculation that's driving a lot of the trading and volatility, and not investors looking at any kind of long-term valuation of the business. While there's still a lot to like, remember that the company is still losing money, so it's a matter of all the growth generating profits -- or more accurately, when that happens. 

I own shares, and I'm planning to hold. If you buy, or own shares, just understand that there will be a lot more weeks like this over the next few months or longer. However, if the company continues reporting record quarters, eventually the market will notice. Full earnings are next week. Stay tuned to Fool.com for more analysis.