Berkshire Hathaway
A holding company in Omaha, Nebraska, that owns other businesses and leaves them alone.
What it does
Berkshire Hathaway is a holding company. It does not make a product of its own — it owns other businesses outright and lets them run themselves. The largest of them sell insurance, haul freight by rail, and generate and distribute energy; the rest manufacture, retail and provide services across most of the American economy.