The D.C. Circuit issued an opinion on March 15, 2013, finding that FERC lacks jurisdiction to penalize alleged manipulation of natural gas futures contracts, even where the conduct affects natural gas prices. FERC had levied a $30 million fine against Brian Hunter, a former natural gas trader for hedge fund Amaranth, for allegedly manipulating the settlement price for natural gas futures contracts. Hunter appealed the fine, claiming that Congress vested the CFTC with exclusive jurisdiction over commodities futures contracts. The CFTC, which had initiated its own enforcement proceedings against Hunter one day before FERC filed its proceeding, joined in the appeal in support of Hunter's position.

The D.C. Circuit sided with Hunter and the CFTC and against FERC in a battle it described as a "jurisdictional turf war." The court held that language in the Energy Policy Act of 2005 giving FERC the authority to regulate manipulation in energy markets was insufficient to overcome a provision in the Commodity Exchange Act which confers exclusive jurisdiction on the CFTC over futures contracts, including those involving energy products. The court disagreed that FERC had concurrent jurisdiction with the CFTC when manipulation in the gas futures market impacts prices in the physical gas market.