Has Warren Buffett lost his touch?

Warren buffett’s birthday present arrived early this year. On August 28th, two days before America Inc’s favourite great grandpa turned 94, his bricks-to-motor-insurance conglomerate, Berkshire Hathaway, reached a market value of $1trn. It became only the eighth American company to claim that title and, as a child of the Nebraskan heartland, the first not to emerge from the west-coast tech scene. Its class-A shares now change hands for…