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

NYSE

99 Cents Only Stores, up $1.76 at 20.46

The New York Post reported that private-equity firm Apollo Management could bid up to $24 a share for the discount store operator.

Patriot Coal Corp., down $1.47 at $12.86

The coal producer said it expects coal costs to rise as production declines by about 450,000 tons in the third quarter.

The St. Joe Co., up $1.12 at $18.20

Investment fund Fairholme Capital is boosting its stake in the Florida real estate developer to 50 percent.

Nasdaq

Research In Motion Ltd., down $5.61 at $23.93

The Blackberry maker reported a sharp drop in net income and revenue and said it sold far fewer tablet computers than it expected.

Diamond Foods Inc., up $9.07 at $87.30

The maker of Pop Secret popcorn and Emerald Nuts reported a 27 percent jump in its fourth-quarter net income on higher sales.

Netflix Inc., down $14.06 at $155.19

Shares of the online movie rental company continued to fall a day after lowering its expectations for U.S. subscribers.

Yahoo Inc., up 8 cents at $14.97

The Wall Street Journal reported that private-equity firm Silver Lake Partners is a potential bidder of the Internet company.

EBay Inc., up $1.65 at $33.69

A Wedbush analyst upgraded the online seller's stock, saying that its PayPal division will grow as mobile payments take off.