Shares of Pandora dropped nearly 20% shortly before the closing bell, after tripping two circuit breakers in 10 minutes.

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Monday's announcement comes one week after Circuit City said it was closing 155 of its more than 700 stores in 55 markets by the end of the year and firing about 17.0% of its U.S. work force.

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The announcement comes one week after Circuit City said it was closing 155 of its more than 700 stores in 55 markets by the end of the year and firing about 17.0% of its work force in the U.S. It also said it was considering all options to restructure.

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"That's why Circuit City and Radio Shack are closing so many stores, " Davidowitz says.

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Circuit City (nyse: CC - news - people ) said it was closing 155 of its more than 700 stores in 55 markets by the end of the year and firing about 17.0% of its U.S. work force.

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