Stocks that moved substantially or traded heavily Monday on the New York Stock Exchange and Nasdaq Stock Market:
Mattel Inc., down 63 cents at $27.76
The toy maker's cheif executive Robert Eckert will retire at the end of the year and be replaced by its chief operating officer.
Cooper Industries PLC, up $1.37 at $53.51
The electrical products maker is being added the S&P 500 Index, replacing asset-management company Janus Capital Group.
Pharmasset Inc., up $61.47 at $134.14
Gilead Sciences agreed to buy the drug developer for about $11 billion in a big bet on its experimental hepatitis C treatments.
Expedia Inc., down 56 cents at $26.90
The online travel company bought Renren Inc.'s interest in Chinese online travel company eLong Inc. for about $72.4 million.
BSD Medical Corp., up 44 cents at $3.06
The cancer treatment developer said that the Food and Drug Administration approved its device that helps treat cervical cancer.
Regeneron Pharmaceuticals Inc., up $5.19 at $55
The biopharmaceutical company said that the Food and Drug Administration approved its treatment for age-related vision loss.
Research In Motion Ltd., down 83 cents at $17.36
A JMP Securities analyst downgraded the BlackBerry maker's stock rating saying that it faces competition from cheaper smartphones.
First Cash Financial Services Inc., down $1.39 at $35.62
A Sterne Agee analyst lowered the pawn shop operator's price target to $36 saying clients might not be able to pay off loans in a weak economy.