Chipotle's stock fell sharply in premarket trading on Wednesday following a weak earnings report on Tuesday.
Shares were down more than 6 percent before the bell.
In addition, JPMorgan, which recently downgraded Chipotle to neutral, maintained its December 2016 stock price target of $465.
It closed Tuesday at $475 a share.
Chipotle beat Wall Street's earnings expectations on Tuesday, but shares fell as it revealed a wider criminal probe into the company's recent food-safety scandal.
Chipotle said federal prosecutors in central California wanted 3 years' worth of information on food safety matters; the Mexican food chain is cooperating with the probe.
Shares in the one-time Wall Street darling fell 2.5 percent in after-hours trading. The stock has plunged in recent months amid a nationwide outbreak of E.coli at its restaurants that sickened dozens. Sales at established restaurants fell 14.6 percent in the fourth quarter.
"The fourth quarter of 2015 was the most challenging period in Chipotle's history, but the Centers for Disease Control and Prevention has now concluded its investigation into the recent E. coli incidents associated with Chipotle," Steve Ells, founder, chairman and co-CEO of Chipotle, said in a statement.