Cheap oil is creating headaches for the Wall Street firms that bankrolled America's oil boom. Banks usually go through "redetermination" in the fall, during which they reevaluate the amount of financing they will provide based on the amount of oil a company can pump at current prices. There could be an increase in bankruptcies "if the financial sector gets scared or handcuffed," said Riccardo Bertocco, a partner with Bain & Company who specializes in oil and gas.