JPMorgan could be fined at least $500 million by U.S. energy market regulators after they accused the bank of manipulating energy prices, reports the New York Times.

The U.S. Federal Energy Regulatory Commission has found JPMorgan devised “manipulative schemes” that transformed “money-losing power plants into powerful profit centers,” the Times reports. The NYT also gained access to a confidential U.S. government document that allegedly reveals illegal trading on California and Michigan electricity markets.