Take a look at some of Tuesday's midday movers:
David Einhorn's Greenlight Capital took new positions in health insurers, highlighting managed case companies Cigna and Coventry Health Care . Meanwhile, Dell and Best Buy fell on news Einhorn was exiting both companies.
Domino’s Pizza rose after the country’s second largest pizza chain reported a better than expected profit.
WebMD lost ground as it cut its 2012 forecast and projected a second-quarter loss.
Boyd Gaming fell as its earnings and revenues fell below Street expectations.
Lennox International also fell after its revenue missed analysts’ estimates. Lennox is a heating and cooling systems maker.
Ryder rose after it raised its fiscal 2012 outlook.
Peabody , the nation’s largest coal miner, lost ground after it reported lower second-quarter earnings and forecast a third-quarter profit below Wall Street expectations.
Rockwell Collins fell after the supplier of avionics and other electronic systems for planes reported weaker-than-expected earnings.
Bruker slid to a three-year low as it warned of disappointing profits due to a weaker euro and softening customer demand in Europe.
RadioShack hit an all-time low after UBS downgraded it to "sell" from "neutral."
CampbellSoup lost ground after it said sales would come in below its previous target of 3 to 4 percent growth in 2013.
For-profit education companies, including Strayer, Apollo and ITT Educational Services fell after DeVry’s disappointing fourth-quarter outlook.