Nike and Overstock.com skid while Ignyta and Party City jump

Stocks that moved substantially or traded heavily Friday:

Nike Inc., down $1.48 to $63.29

The athletic apparel retailer had a solid quarter but sales in North America remained weak.

Papa John's International Inc., down $2.33 to $56.90

The pizza chain said founder John Schnatter will step down as CEO on Jan. 1.

Ignyta Inc., up $11.30 to $26.85

Swiss drugmaker Roche will buy the cancer drug developer for $27 a share, or $1.79 billion.

Celgene Corp., down $1.55 to $106.33

The company said an experimental lymphoma treatment regimen failed in a late-stage clinical trial.

UnitedHealth Group Inc., down $1.69 to $220

The health insurer said it will buy Empresas Banmédica of South America for $2.8 billion.

Party City Holdco Inc., up $1.75 to $13.95

The party supply company said it will buy back $242 million in stock from private equity firm Advent International.

Overstock.com Inc., down $1.70 to $65.75

The online discount retailer has climbed along with the price of bitcoin, and fell in tandem with it Friday.

AAR Corp., down $3.74 to $40.21

The airplane maintenance company's second-quarter profit and sales fell short of Wall Street estimates.