DuPont, Edward Lifesciences, Penn West, A. Schulman and Salix are big market movers

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

NYSE

The DuPont Co., down $3.43 to $77.07

The chemical company rejected hedge fund Trian Fund Management's proposal to place four nominees on its board of directors.

Edwards Lifesciences Corp., up $13.29 to $148.64

Researchers presented positive data for the medical device maker's third-generation heart-valve replacement system.

Life Time Fitness Inc., up $3.48 to $70.68

The gym operator will sell itself to two private-equity firms for more than $2.8 billion.

Penn West Petroleum Ltd., down 5 cents to $1.37

The oil and gas company and its industry peers saw shares fall as the price of crude oil fell to its lowest level in six years.

Nasdaq

A. Schulman Inc., up $1.86 to $43.92

The plastic compounds and resins supplier will buy privately held Citadel Plastics for $800 million.

Salix Pharmaceuticals Ltd., up $3.35 to $172.75

Valeant raised its offer for the drug maker by more than $1 billion, forcing rival bidder Endo International out of the running.

Kandi Technologies Group Inc., up $1.31 to $14.54

The Chinese vehicle maker reported a profit for 2014 on an 80 percent boost in revenue, driven by demand for electric vehicles.

iDreamSky Technology Limited, down $3.60 to $7.22

The Chinese maker of mobile and online games provided weaker-than-expected revenue guidance.