What's happening: Natural gas refueling leader Clean Energy Fuels (NASDAQ:CLNE) stock is down 14% today after it was announced that co-founder, board member, and largest shareholder T. Boone Pickens would sell as many as 3 million shares in the company. 

Why it's happening: It's not out of the ordinary for a stock to move on news that a major shareholder has sold or bought shares, but rarely to this degree, over what works out to be about 17% of Pickens' total holdings in the company. Clean Energy filed a Form 4 with the SEC yesterday, disclosing that Pickens sold 698,000 shares in recent days, so there could be more short-term pain, since he disclosed he could sell up to 3 million in total. 

Pickens remains vocal in his support of the company, posting this on Twitter this morning:

So while it's unnerving when a major stakeholder in a company -- and a co-founder, no less -- sells shares, let's not project our own situation and investing prospects onto Pickens and his decision. In other words, we don't know Pickens' reasons, so it's dangerous to read too much into it. 

Especially when it has little to no bearing on the company's prospects. 

From a business fundamentals perspective -- toward which we as investors should keep our eyes turned -- Clean Energy continues to grow at a relatively rapid pace, and is easily the most dominant company in natural gas for transportation, both CNG and LNG, with hundreds more stations than the nearest competitors. The company also expanded into the industrial gas supply business last year, with its acquisition of a controlling stake in NG Advantage, to supply a "virtual" pipeline of CNG to industrial users who don't have access to CNG pipelines but can benefit from the low cost. 

The biggest concern with Clean Energy has been its cash burn, largely a product of the big debt load it took on a couple of years back in order to aggressively expand its public station business. And while that initiative hasn't produced the immediate returns many expected, the company's cash from operations and free cash flows are trending upward, as the company produces more cash from its refueling business, and has significantly cut both operating costs and capital expenditures. 

In summary, risk still remains as the business works toward positive cash flows and deals with its large debt load, but Pickens' decision to sell a small part of his stake isn't really a long-term risk for the business, despite its impact on the stock price.