Petrobras, Sarepta Therapeutics, Micron Technology and Novavax are big market movers

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

NYSE

Petrobras SA, down $1.77 to $11.16

The Brazilian oil company's stock tumbled following the country's hard-fought presidential race in which President Dilma Rousseff won re-election.

NQ Mobile Inc., up 52 cents to $9.46

The mobile Internet services company filed its 2013 annual report and accounting firms did not find any fraudulent behavior alleged by a research firm.

Chiquita Brands International Inc., up 20 cents to $14.36

The fresh produce company agreed to sell itself to two Brazilian companies for about $681 million, or $1.3 billion including debt.

Halliburton Co., down $3.39 to $52.39

The oilfield services company's stock lost ground as oil prices continue declining, falling below $80 per barrel on Monday.

Nasdaq

Sarepta Therapeutics Inc., down $7.65 to $15.91

The Food and Drug Administration wants additional data on the biotechnology company's potential muscular dystrophy treatment.

Micron Technology Inc., up $1.24 to $32.30

The technology company's board of directors approved a stock buyback program for up to $1 billion worth of outstanding shares.

Novavax Inc., up 67 cents to $5.80

The drug developer expects to begin early stage studies involving humans of its potential Ebola vaccine in December.

Pain Therapeutics Inc., down $2.20 to $1.95

Pfizer Inc. ended its deal with the biotechnology company to develop a potential extended-release version of the pain killer Oxycodone.