Among the stock activity stories for Tuesday, Oct. 20, from AP Financial News:

NEW YORK (AP) ¿ Boeing Co. fell after an analyst downgraded shares on concerns the aerospace company's marquee aircraft will be delivered late and overweight, corporate cash flow will worsen and projected earnings will need trimming.

HARTFORD, Conn. (AP) ¿ Shares of Werner Enterprises Inc. soared to a new 52-week high a day after the trucking and logistics company posted third-quarter profit that widely beat Wall Street estimates.

PHILADELPHIA (AP) ¿ Shares of Volterra Semiconductor Corp. fell after the chip maker reported third-quarter earnings that disappointed Wall Street in part due to litigation costs that drove operating expenses higher.

NEW YORK (AP) ¿ Packaging Corp. of America fell after the cardboard box material maker forecast fourth-quarter earnings below Wall Street expectations because of lower volumes and selling prices.

NEW YORK (AP) ¿ Shares of Chinese education services provider New Oriental Education and Technology Group Inc. tumbled after its quarterly results came in short of analysts' expectations because of the negative impact of the swine flu on enrollments.

WASHINGTON (AP) ¿ Shares of Boston Scientific plummeted after the medical device maker forecast disappointing earnings on slower sales of its implants.

NEW YORK (AP) ¿ Shares of MetroPCS Communications Inc. and Leap Wireless International Inc. fell as Goldman Sachs predicted disappointing quarterly results.

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