Retail giant Wal-Mart Stores Inc. has incited its worst stock drop in more than 27 years, after the company predicted a significant drop in its annual profit on Wednesday. The announcement sent the company's stocks plummeting 10 percent to $60.30 in New York, wiping out more than $21 billion in shareholder wealth, according to Bloomberg Business.

The announcement was especially bad for the top 10 shareholders of the company, since they collectively own about two-thirds of Wal-Mart's outstanding stocks, amounting to about $14.7 billion.

One of America's wealthiest families, the Waltons, were hit very hard with the announcement.

The Walton family owns Walton Enterprises, an investment vehicle controlled by several key members of the Wal-Mart family. Overall, Walton Enterprises holds about 1.4 billion shares of Wal-Mart, or about 44 percent of the total shares outstanding, according to S&P Capital IQ, reports AZ Central. Overall, the Waltons lost an estimated $12 billion dollars due to the stock drop.

Famed investor Warren Buffet, one of the company's major stockholders, also suffered a significant loss. Buffet's Berkshire Hathaway currently owns about 60.4 million shares of the company, translating his losses to about $405 million.

The drop in the company's stocks is the biggest since January 1988. However, the decline did not happen overnight, as Wal-Mart's stocks were already down 22 percent this year even before the company's grim announcement.

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