Vistra Corp. is a holding company, which engages in the provision of electricity and power generation. It operates through the following segments: Retail, Texas, East, West, Sunset, and Asset Closure. The Retail segment sells electricity and natural gas to residential, commercial, and industrial customers. The Texas and East segments are involved in electricity generation, wholesale energy sales and purchases, commodity risk management activities, fuel production and fuel logistics management. The West segment represents the company's electricity generation operations in CAISO. The Sunset segment includes generation plants with announced retirement plans. The Asset Closure segment refers to the decommissioning and reclamation of retired plants and mines. The company was founded in 1882 and is headquartered in Irving, TX.