Mizuho analyst Jeremy Scott downgraded Chipotle Mexican Grill (CMG) to Underperform while raising his price target for the shares to $330 from $300. The stock closed yesterday up $12.72, or 3%, to $463.89.

After an 80% rally since the new CEO appointment, Chipotle shares currently price in an "aggressive recovery" in both comps and margins, Scott tells investors in a research note. The analyst does not see "clear catalysts that can justify significant earnings upside."

As such, he recommends investors "reduce their risk."