The move was taken as a sign that lenders are beginning to share in the optimism that oil and gas producers have been enjoying since the beginning of the year, with prices staying above $50.

While some banks seem to be sharing some of the optimism, others are more cautious. A recent analysis from Bloomberg Gadfly's Lisa Abramowicz reveals that a lot of energy companies with revolving credit lines are tapping deep into these resources. Abramowicz cites data from Bloomberg Intelligence that shows at least 11 companies have used up more than two-thirds of their credit lines.

Banks, Abramowicz says, do not like this, so they may well decide to cut the credit lines of companies they consider risky.