Nvidia, AMR, Lehman Brothers among big movers

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

NYSE

AMR Corp., up 21 cents at $4.83

American Airlines may cut at least 6,000 jobs this year, or 8 percent of its staff, while trying to offset rising fuel costs.

Lehman Brothers Holdings Inc., up 49 cents at $22.85

As turmoil continues in the credit markets, speculation swirled that Barclays PLC may buy the investment bank at a discount.

Toll Brothers Inc., down 1 cent to $18.85

Moody's Investor Service cut the senior unsecured rating on the homebuilder to junk status as falling prices continue crimping margins.

Aetna Inc., down $2.65 at $37.14

A Goldman Sachs analyst downgraded the health insurer's stock to "Sell" from "Neutral" because of crumbling profit margins.

General Motors Corp., up 14 cents at $10.12

A JPMorgan analyst said the automaker isn't in immediate danger of bankruptcy, but will need to raise about $10 billion in cash.

NASDAQ

Nvidia Corp., down $5.54 at $12.49

Weakness in certain markets and higher competition caused the graphics chip maker to cut its second-quarter revenue outlook.

Penn National Gaming Inc., up $1.06 at $29.66

A $5.82 billion takeover of the casino operator by Fortress Investment Group and Centerbridge Partners has been called off because of declining purchase price.

Corel Corp., up $1.43 at $10.75

The software maker's quarterly profit dropped 60 percent on higher sales and marketing costs, but still topped expectations when adjusted.

Terra/AP