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Proof check

Chapter 2Berkshire Hathaway (BRK-B)

Verified on the Bitcoin blockchain

This chapter's exact text was locked into Bitcoin block #964,946, mined on August 31, 2026 at 10:23 PM UTC. That means it already existed by then and hasn't changed since — proven by the Bitcoin network, not by us. Anyone who tried to backdate or edit it would produce a different fingerprint that wouldn't match this block.

How this was checked

We did the work for you — but every number below is public, so you can re-check each line yourself.

  1. 1 · The proof is for this exact chapter

    The chapter file has a unique SHA-256 fingerprint. It matches the fingerprint recorded inside the timestamp proof — so the proof can only belong to this text, unchanged.

    The file's fingerprint
    98dbd919aae62ad3e8e8bc84944deb1eb261b21313605eef19eb5af4927ada87
    Fingerprint inside the proof
    98dbd919aae62ad3e8e8bc84944deb1eb261b21313605eef19eb5af4927ada87
  2. 2 · The proof is anchored in a real Bitcoin block

    The proof resolves to a Bitcoin block's merkle root — the fingerprint of everything in that block. It matches the merkle root of the real block #964,946 reported by an independent explorer — so this proof genuinely lives in that block.

    Merkle root the proof resolves to
    a9d5a31ab562772692509e5b995c0751012729566a7799d81890295e8b636620
    Merkle root of the real block
    a9d5a31ab562772692509e5b995c0751012729566a7799d81890295e8b636620
  3. 3 · When Bitcoin says it happened

    Block #964,946 was mined on August 31, 2026 at 10:23 PM UTC — the blockchain's own clock, which no one can rewind. So this chapter provably existed by then.

    A note on the time: we show it in UTC — the fixed, universal clock used for proofs. A block explorer like mempool.space usually shows the same moment in your local timezone, so the clock time can look a few hours different. It's the exact same instant.

Want to verify it entirely on your own? Download the .ots proof and the chapter file, then drop both into opentimestamps.org (or run the ots tool). It will independently confirm the same block and time shown above — nothing here depends on trusting this site.