Illinois was essentially an afterthought in the transaction, which focused on Texas and markets east of Chicago. Vistra, like others before it, has complained that market rules—in this case, overseen by regional power-grid manager Midcontinent Independent System Operator—don't appropriately value the output of its facilities. "These plants, especially those operating in the irreparably dysfunctional MISO market, remain economically challenged," Vistra said in today's press release. "Today's retirement announcements are also prompted by upcoming Environmental Protection Agency filing deadlines, which require either significant capital expenditures for compliance or retirement declarations."