Below is a video clip from the FT outling the reasons for the debt build up in the energy industry which is making investors nervous. Fracking has been partly responsible for the increase in oil output in the US by 400m barrels a day between 2010-2015. It was encouraged by high oil prices and also meant the sector took on a lot more debt – assuming that oil prices would stay above $100 a barrel. However as oil prices collapsed to around $30 a barrel oil extraction companies are finding it increasingly difficult to service their debt. Worth a look and with some very informative graphs.