Warren Buffett losing some mojo on his economic 'moats'

Warren Buffett has carved out a core stock-picking strategy of investing in companies with strong economic "moats," businesses that have built, fortified and generated success from well-known brands that make it difficult for them to succumb to competitive forces. When Berkshire Hathaway Inc , the conglomerate Buffett has run since 1965, releases quarterly results on Friday - which will follow with his annual gathering in Omaha, Nebraska - it is likely to show that his largest equity-m