About BuffettKnowledge

Built for investors who want more than quotes.

The most comprehensive English-language archive of Warren Buffett's shareholder letters — from the first Partnership letter in 1956 to the 2025 farewell. Every concept, company, and person is tagged, linked, and explorable.

What You Can Do Here

70 Years of Letters

Every partnership letter (1956–1970), Berkshire shareholder letter (1971–2025), and key special letter — fully indexed and searchable.

Concept Graph

150+ investment concepts cross-referenced across letters, with first appearance, refinement, and key-quote tags.

Smart Search

Search by concept, company, person, or keyword. Every entity is linked — click through to see every letter that mentions it.

AI-Powered Q&A

Ask natural-language questions about any letter or concept. Our RAG engine retrieves the relevant passages and generates an answer.

What's Included

  • 68 partnership & Berkshire shareholder letters (1956–2025)
  • 150+ investment concepts with cross-reference tags
  • 60+ company profiles with mention timelines
  • 17 key people — from Graham to Munger to Abel
  • 3,900+ cross-references between letters, concepts, and companies
  • Key quotes extracted from every letter
  • Interactive knowledge graph — explore concept relationships visually
  • AI Q&A — ask questions in plain English

How to Navigate

Letters — Browse all letters chronologically. Filter by type (Partnership / Berkshire / Special). Click any letter to read the full text.
Concepts — Explore 150+ investment concepts. Each concept page lists every letter that discusses it, tagged by relevance.
Companies — See every Berkshire position and major holding. Each page shows all letters mentioning that company.
Graph — Visualize connections between concepts. Zoom, pan, and click any node to dive into that concept.
Ask AI — Type any question about Buffett's letters. The AI retrieves relevant passages and answers in its own words.

Data Sources

All letter texts are sourced from the official Berkshire Hathaway website and open-source transcript projects. We do not claim copyright over any material — it is provided for educational and research purposes.

How Concepts Are Tagged

Every letter is read and tagged with the investment concepts it discusses. A cross-reference is created when a concept is central to a letter (marked as “key”), marks its first appearance (“first”), represents a refinement of prior thinking (“refinement”), or is simply mentioned (“mention”).

Company and people mentions are identified by keyword matching and manual review. Each mention includes the relevant passage from the letter.

Contribute

This is an open project. If you find an error in letter text, concept assignment, or cross-reference, we welcome corrections. Open an issue or pull request on GitHub.

View on GitHub

BuffettKnowledge is not affiliated with, endorsed by, or connected to Berkshire Hathaway Inc., Warren Buffett, or Charlie Munger. All trademarks belong to their respective owners.