Information provided by Theflyonthewall.com

Chesapeake Energy (CHK) rallied 8% after announcing it would appoint a new non-executive chairman in the near future to replace CEO Aubrey McClendon in that role. McClendon, who will remain on as CEO, also agreed to an early termination of the well participation program that has drawn a firestorm of recent backlash from media, investors and regulators.

Dow component Pfizer (PFE) reported earnings that beat consensus but lowered its full year forecast to account for the divestiture of its Nutrition business.

Among other companies reporting earnings, advancers included Huntsman (HUN), Archer Daniels Midland (ADM) and Masco (MAS); decliners included Emerson (EMR), Domino's Pizza (DPZ), Avon Products (AVP) and Jacobs Engineering (JEC).

Automakers reported April U.S. sales figures, with Volkswagen (VLKAY), Chrysler (FIATY) and Toyota (TM) reporting gains and GM (GM) and Ford (F) both reporting declines.

Among the notable market gainers Tuesday were PLX Technology (PLXT), up 67%, on news it will be acquired by Integrated Device Technology (IDTI) for $7 per share in cash and stock, and P.F. Chang's (PFCB), up almost 30%, after agreeing to be acquired and taken private by Centerbridge Partners for $51.50 per share in cash.

Also higher were shares of Sears Holdings (SHLD), up about 21%, after saying first-quarter domestic same store sales fell 1.3%, which was a significant improvement from the declines seen in the same period last year, and forecasting a return to earnings from continuing operations in the quarter.

In contrast, Pep Boys (PBY) fell nearly 25% after the company warned its first-quarter results may miss expectations and its potential acquirer, the Gores Group, said that "the serious deterioration in the Pep Boys business" may constitute a material adverse effect or may violate covenants contained in its merger agreement.

Also declining was Herbalife (HLF), down almost 20%, following its earnings report and its subsequent conference call, during which David Einhorn of Greenlight Capital questioned the company.