This segment is from Thursday's edition of 'Digging for Value', in which sector analysts Joel South and Taylor Muckerman discuss energy & materials news with host Alison Southwick. The twice-weekly show can be viewed on Tuesdays & Thursdays. It can also be found on Twitter, along with our extended coverage of the energy & materials sectors @TMFEnergy.

Volatility is standard operating procedure for most stocks of disruptive companies in the early going. This trait is clearly evident in the shares of Clean Energy Fuels (CLNE -0.87%) and SolarCity (SCTY.DL). While Clean Energy Fuels has been busy signing big deals with industry titans like United Parcel Service (UPS -1.51%), SolarCity has been successfully competing with SunPower (SPWR -1.02%) in the photovoltaic space. For more on these two hot stocks, check out the video below.

In a portfolio, volatility can be balanced with stability offered by companies like these nine: