Where the supply sits

The BTC Register · Explanation reviewed 6 Oct 2026

What does ownership mean here?

This register classifies balances by the company, fund or government recorded as holding the bitcoin. It does not identify every beneficial owner behind those entities. In particular, an individual can hold fund shares while the underlying bitcoin is counted in the fund category. Adding that investor’s indirect exposure to the same fund balance would count the same coins twice.

IBIT’s prospectus describes its shares as fractional beneficial interests in the trust’s net assets, rather than shares in BlackRock itself.[1] Our classification therefore puts the trust’s bitcoin under funds, not under BlackRock’s corporate treasury. The distinction is about the holding structure, not a claim that every fund investor is an institution. The IBIT versus Strategy guide explains why a trust and a listed company require different readings.

What is included, and what is missing?

The current company file covers 181 listed companies, retrieved 30 Oct 2026. It is a reported-data register, not a survey of all private businesses or investment vehicles. A retrieval date says when the source was collected; it does not prove that a purchase happened that day. The individual company records retain their source links so the origin of each balance can be checked.

The fund input includes only IBIT, with its own issuer observation date. It is not the complete US spot ETF market, nor all global bitcoin investment products. The archived aggregate ETF record overlaps IBIT and is excluded, rather than added on top. A larger residual caused by narrower coverage is not evidence that individual investors acquired more bitcoin.

Government holdings total 217,143 BTC in this ledger. The source records are dated 31 Dec 2025; a new weekly edition does not refresh those estimates. Transfers, sales and incomplete attribution could change the true balance. They should not be presented as a verified current inventory of sovereign reserves.

Why assumed losses change the answer

We subtract 3,700,000 BTC as assumed lost or inaccessible. This is a modelling choice, not a measured address category. Increasing assumed losses lowers the residual by the same number of bitcoin; reducing them raises it. Missing institutional coverage works in the opposite direction. These uncertainties are not eliminated by displaying more decimal places.

Which historical comparisons are valid?

The comparable series begins 31 Aug 2026. Its consecutive observations use the same IBIT-only fund coverage and loss assumption. Earlier estimates used different fund inputs and remain archived outside that series. Comparing them as though the definition had stayed constant would confuse a methodology change with a change in ownership.

The 50% scenarios start from this same residual. They are conditional calculations, not a forecast of a market event or a date when institutions will control Bitcoin. Read the methodology before reusing a percentage. For research workflows, see the sample data, coverage notes and request path. Tell us which free datasets and formats would help your research.

Sources

[1] iShares Bitcoin Trust ETF prospectus, 31 July 2025, with 21 November 2025 supplement. Checked 6 Oct 2026.