The following video is from Tuesday's Digging for Value, in which host Alison Southwick, and Motley Fool energy analysts Taylor Muckerman and Joel South, get to the heart of the biggest stories in energy investing today.

In this segment, Joel South discusses the nice price appreciation in Clean Energy Fuels (CLNE 8.00%) today. While there are many reasons for insiders to sell shares, there is only one reason to buy. Today, Clean Energy Fuels CEO Andrew Littlefair saw significant value in the company, and picked up 127,000 shares.