A bi-partisan group of House members sent a letter to the Commodity Futures Trading Commission (CFTC) asking for an investigation into the alleged manipulation of the market for ethanol credits. The group of Representatives, all from the Midwest, said in their letter that price volatility in the market over the last year could be due to trading outside normal supply-and demand forces. Renewable identification numbers (RINS) are used to identify the credits and were created to be traded in the fuel supply chain and not in financial markets. The prices per credit fluctuated over the year from a few cents upwards to a high of $1.45 and back down to 30 cents. The oil industry and ethanol producers have different opinions on what has caused the price volatility. Sens. Grassley (R-IA) and Stabenow (D-MI) sent letters to the EPA and the CFTC respectively in September in regards to the manipulation of the RIN market. When the senators wrote their letters the RIN prices were around 70 cents. The lawmakers believe the CFTC and the EPA need to coordinate efforts to properly monitor the RIN market.