Investors who have bought in cheap--one Philly source says the stock exchange has doubled in value since last year--could be hoping to sell.

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Over time business resale values tend to be similar to small-cap value companies that trade on the stock exchange.

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The New York Stock Exchange-listed company has lost about 40% of its value in the past two days.

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As local and international investors have fled Japan's stock market, some 40% of the 1, 500 companies that are the bluest chips of Japan (the first section of the Tokyo Stock Exchange) trade below breakup value (a price-to-book value of less than one).

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Thursday's trading appeared to continue a pattern of unusual moves over the past week between the stock and foreign-exchange markets, where a fall in Japanese share prices seemed to be driving down the value of the dollar against the yen.

WSJ: 5.2% Drop Takes Tokyo Stocks Into a Correction