Berkshire has also been hit by big declines in two of its largest stock market investments: American Express, which is down by 24 per cent this year; and IBM, which is down 13 per cent.
Mr Buffett's operating results have not been poor, however, with Berkshire's net earnings up 18 per cent to $18.6bn in the first nine months of the year, and book value up 3.3 per cent.
The fall in Berkshire shares this year comes against a 3 per cent return from the S&P 500, including dividends. It is only the 11th negative year since Mr Buffett seized control in 1965, and the worst underperformance relative to the S&P 500 since 2009, when the wider stock market recovered much more sharply from the effects of the financial crisis.
In a change to the format of his annual letter to shareholders this year, Mr Buffett displayed Berkshire's annual share price record as well as its book value.
"Over time, stock prices and intrinsic value almost invariably converge," he wrote in February. "In our view, the increase in Berkshire's per-share intrinsic value over the past 50 years is roughly equal to the 1,826,163 per cent gain in market price of the company's shares."