Target says a small percentage of the gift cards it sold won't work properly — more bad news following on the heels of a security breach affecting some 40 million credit and debit cards. Justin Sullivan/Getty Images hide caption

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Carlos Slim Helu (left) talks with Steve Forbes of Forbes magazine. The magazine lists the Mexican telecom mogul as the world's richest man, with a net worth of $73 billion. Jeremy Piper/AP hide caption

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Twitter made its debut on the New York Stock Exchange in November. Both the social media giant and the relative newcomer Snapchat are valued in the billions, but neither company has yet turned a profit. Emmanuel Dunand/AFP/Getty Images hide caption

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A Boeing 737 takes off from Ronald Reagan Washington National Airport in Arlington, Va. Demand remains high for 737s and 777s, helping the company weather problems with its 787 earlier this year. Saul Loeb/AFP/Getty Images hide caption

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Several Silicon Valley entrepreneurs are developing services that manage consumers' investment portfolios with algorithms rather than people. iStockphoto hide caption

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Senate Majority Leader Harry Reid (D-Nev.) talks to reporters at the Capitol in Washington, last Thursday. Reid has promised a vote no later than Jan. 7 on a measure to extend jobless benefits for three months. J. Scott Applewhite/AP hide caption

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