它BRK很大一部分盈利来自于profit from operating business

Ownership of Operating Businesses: Berkshire fully owns a diverse portfolio of companies, including GEICO (insurance), BNSF (railroads), and Duracell (batteries). These subsidiaries generate profits through their operations, contributing steady cash flow. The insurance businesses, in particular, provide “float”—premiums collected before claims are paid—which Buffett uses as capital for investments.