On the face of it, this has been a switchback year for Warren Buffett. His master company, Berkshire Hathaway, collapsed into horrendous loss in the first quarter, and then staged a roaring recovery in the second.

The reality has been slightly different. The bulk of the company – some two-thirds by asset value – is an old-style conglomerate, stretching from insurance to housebuilding. That suffered a mere 13 per cent drop in profits in the first quarter and 31 per cent in the second. But it has been dwarfed by paper losses and gains in the markets.