S&P 500 top movers: Chipotle Mexican Grill Inc (CMG: NYSE) advances to all-time highs

• S&P 500 Index remains on track to close little changed on Wednesday.
• Chipotle Mexican Grill Inc shares sore on rating upgrage.
• DISH Network Corp stock slumps as company announces $2 billion convertible notes offering.

The S&P 500 Index (SPX) opened the day little changed on Wednesday and seems to be having a tough time making a decisive move in either direction. As of writing, the SPX was up 0.07% on a daily basis at 3,697.

S&P 500 top movers

Earlier in the day, Stifel announced that it upgraded Chipotle Mexican Grill Inc (CMG: NYSE) stock to 'buy' and raised its price target to $1,500 from $1,400. Boosted by this development, CMG surged to a record high of $1,422.22 and was last seen up 5% on the day at $1,413.

Among the other top daily percentage gainers, ServiceNow Inc (NOW: NYSE), Marathon Oil Corp (MRO: NYSE) and Cimarex Energy Co (XEC: NYSE) shares are up between 3.4% and 3.7%.

On the other hand, DISH Network Corp (DISH: NASDAQ) shares suffer heavy losses after the company announced $2 billion convertible notes offering. At the moment, DISH is down 9.22% at $32.39 as the biggest decliner of the day.