Reuters: A U.S. senator is pressing the Environmental Protection Agency to release more information on the market used to trade biofuel credits, known as RINs, after suggestions of manipulation by Wall Street banks. "I'm concerned about recent reports of manipulation or exploitation of the RIN market," Charles Grassley, an Iowa Republican, said in a letter to U.S. EPA administrator Gina McCarthy. "Allegations that the opaqueness of this market is leading to abuse and exploitation by individuals or firms...