Tupperware, Navistar, H&R Block, Heartware and SFX are big market movers

Stocks that moved substantially or traded heavily Wednesday on the New York Stock Exchange and the Nasdaq Stock Market:

NYSE

Tupperware Brands Corp., up $2.95 to $52

The maker of food storage and serving products gave an upbeat sales outlook citing performance in international markets.

Navistar International Corp., down 75 cents to $16.61

The truck and engine maker reported a wider third-quarter loss and said the government may take action against it in a dispute over environmental certification of heavy-duty diesel engines.

GeoPark Ltd., up 4 cents to $3.94

The Latin American oil and gas exploration company reported the discovery of a new oil field near its Jacana field in Colombia.

H&R Block Inc., up $2.47 to $35.42

The tax preparation company reported better-than-expected first-quarter results and announced a $3.5 billion stock buyback plan.

Nasdaq

HeartWare International Inc., down $16.99 to $64.82

The medical device company, focusing on heart pumps, is buying privately held Valtech Cardio for an undisclosed amount.

Republic Airways Holdings Inc., down 2 cents to $3.01

Teamsters officials have declined to force a vote on the struggling regional airline's final contract offer to its pilots.

The Fresh Market Inc., up 83 cents to $21.99

The specialty grocery store operator named veteran food retail executive Richard Anicetti as the company's new CEO.

SFX Entertainment Inc., down 34 cents to 67 cents.

The live and digital entertainment company said that credit rating downgrades are causing short-term disruptions to its business.