Stocks to Watch: RailAmerica, Hewlett-Packard, BHP Billiton and More...

Stocks turned negative in another choppy session Thursday. Wall Street cheered as Berkshire Hathaway said it will invest $5 billion in Bank of America, but remained concerned ahead of Bernanke's Jackson Hole speech at the end of the week.

The Dow Jones Industrial Average turned negative after logging a three-day rally in the previous session.

Here are five stocks that are on the move:

RailAmerica
The railroad operator was upgraded to buy from hold at Stifel Nicolaus.

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Hewlett-Packard
The computer company was downgraded to sector perform from outperform at RBC Capital on fears of brand deterioration.

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American Eagle Outfitters
The apparel retailer was upgraded to neutral from sell at Lazard Capital markets citing a balanced risk vs. reward environment.

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BHP Billiton
The natural resources company was upgraded to buy from hold at Societe Generale on valuation.

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Sanderson Farms
The poultry processing company was upgraded to overweight from equal weight at Stephens.

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