Buffett: last year 'subpar' for Berkshire despite profit rise

In his eagerly anticipated annual letter to investors, Buffett warned in 2013 the growth in Berkshire's book value per share may underperform the S&P 500 when measured over a five-year period for the first time. "To date, we have never had a five-year period of underperformance, having managed 43 times to surpass the S&P over such a stretch," he wrote. "But the S&P has now had gains in each of the last four years, outpacing us over that period. If the market continues to advance in 2013, our streak of five-year wins will end." Buffett said he expects growth in Berkshire's "intrinsi...