Either that, or they should stick within their circle of competence, like Warren Buffett, who avoids technology altogether.

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The emphasis ought to be on widening the circle of competence, as Google is trying to do with its foray into handheld devices.

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Buffett buys companies that are simple to understand, he says, and are within his circle of competence because he wants to have a good idea of what the future business is going to look like.

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You stay within the circle of competence.

FORBES: Mohnish Pabrai: Invest Wise & Nap Daily