U.S. banks, like their global counterparts, have had a rough year as falling oil prices and worries about slowing growth in China contributed to weakness in credit markets, pressuring revenue growth. The new year also started on a grim note as oil prices fell below $30 a barrel and stock prices slumped. Reflecting this, Bank of America’s provision for credit losses in global banking increased by $264 million in the quarter ended Dec. 31, mainly due to higher energy-related charge-offs and reserve increases for energy exposure.