Summary and review ofBuffettology

Reviewed by Diario de un Inversor · UpdatedJune 13, 2026

Our review

«Buffettology» is one of the most serious attempts to codify Warren Buffett's analytical method into a replicable step-by-step process. Mary Buffett, who had twelve years of direct access to the investor's family and circle, and David Clark break down Buffett's company selection process with a level of detail that the shareholder letters do not explicitly provide. The book is organized around a set of quantitative and qualitative criteria: sustained return on equity, predictable earnings growth, pricing power, absence of significant debt, and management that is honest with shareholders. The most practical tool the book offers is a spreadsheet framework for calculating intrinsic value using earnings-per-share projections and expected return rates. The most frequent critique is that the book presents the process as more mechanical than it probably is — Buffett himself has acknowledged that qualitative judgment is not quantifiable. Even so, for the investor who wants a structured Buffettian analysis framework, it is one of the most useful starting points available.

Key takeaways

• Sustained return on equity (ROE) over several years is one of the best indicators of a real competitive advantage.
• Predictability of earnings growth is more valuable than growth itself: it allows intrinsic value to be calculated with a smaller margin of error.
• Buffett treats investing in stocks as buying a business, not speculating on price movements.
• The purchase price matters as much as business quality: an excellent company bought at too high a price can produce mediocre returns.

Fact

Published in 1997. Mary Buffett was Warren Buffett's daughter-in-law from 1981 until her divorce from Peter Buffett in 1993, during which time she had direct access to the investor's family circle.