Family Dollar, Trulia, Horizon Pharma, Tyson Foods, and AcelRx are big market movers

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

NYSE

Family Dollar Stores Inc., up $15.08 to $75.74

The discount retailer is being bought for $8.5 billion by rival Dollar Tree, which is significantly broadening its reach as it looks to fend off Wal-Mart.

Trulia Inc., up $8.69 to $65.04

The real estate website operator is being bought by rival Zillow in a $3.5 billion all-stock deal expected to close next year.

Tyson Foods Inc., up $1.02 to $40.56

The meat processor reported a jump in quarterly sales and plans to sell its Mexican and Brazilian poultry units for $575 million.

Armstrong World Industries Inc., down $5.77 to $49.60

The flooring products and ceiling systems maker reported lower-than-expected quarterly profit and cut its full-year guidance.

Nasdaq

Horizon Pharma Inc., down $4.75 to $9.15

The drug developer said two of its key products will be placed on exclusionary lists by the two largest pharmacy benefit managers.

AcelRx Pharmaceuticals Inc., down $4.44 to $6.39

The Food and Drug Administration rejected the company's painkiller-dispensing device Zalviso, partly citing data on shelf life.

Lincoln Electric Holdings Inc., up $3.28 to $70.05

The welding and cutting products company reported a better-than-expected second-quarter profit and declared a quarterly dividend.

Alliance Resource Partners LP, up $1.44 to $50.09

The coal mining company reported better-than-expected quarterly profit and revenue and increased its cash distribution.