In the following video, Motley Fool financial analyst Matt Koppenheffer talks about the top two holdings in his own personal portfolio, Wal-Mart (NYSE:WMT) and Berkshire Hathaway (NYSE:BRK.B). He tells us why he thinks Wal-Mart's competitive moat is an enduring one and what he likes about the structure of giant Berkshire Hathaway.

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