Buffett's Prescription for Portfolio-Building

"The art of investing in public companies successfully is little different from the art of successfully acquiring subsidiaries. " 1996 Annual Report, Berkshire Hathaway. Here, Buffett provides a standard for understanding the components of a portfolio. The implicit standard for buying, holding or selling centers around a zone of competence (not preference - an all too common mistake) and not popularity, Federal Reserve behavior, or a Wall Street analyst's opinion.