Buffett issued his annual shareholder letter, noting that the value of his tradable stock holdings fell from $354 billion to $272 billion last year, but the value of his unlisted controlling stake has increased and remains well above the value of his tradable stock portfolio. We will always invest the vast majority of their money in stocks - primarily U.S. stocks, although many of these companies will have significant international operations. Berkshire will never be more inclined to hold cash e...