As of June 10, 2025, BlackRock, through the iShares Bitcoin Trust (IBIT), held 662,600 BTC, equivalent to about 3.3% of the circulating supply of 19.83 million coins. An unprecedented amount for a listed vehicle, which is reshaping institutional adoption, liquidity, and the debate on regulation and decentralization of the network.
In brief
- Launch IBIT: January 11, 2024
- Holdings (June 10, 2025): ~662,600 BTC
- Estimated offer share: ≈3.3% of the circulating
- Custody: Coinbase Custody (main) and, from April 9, 2025, also Anchorage Digital Bank (Ledger Insights)
According to the data collected by our editorial team, by cross-referencing SEC filings, iShares announcements, and on-chain trackers, IBIT reached approximately 662,600 BTC as of June 10, 2025 and continued to increase in the following weeks.
Industry analysts we spoke with highlight that net inflows into spot ETFs have been among the main demand drivers in the 2024–2025 period. Direct observation of filings and on-chain records confirms the speed with which these vehicles can accumulate stock in markets with marginal supply.
BlackRock Bitcoin ETF: from niche to institutional standard
The spot ETFs on Bitcoin have lowered the entry barriers for banks, pension funds, and asset managers. Clear governance, regulated custody, and standardized reporting allow allocation in Bitcoin without managing private keys or dedicated infrastructure. The result is an acceleration of institutional adoption and a change in perception: from “experimental” asset to a tactical or strategic component of a portfolio.
Why large allocators prefer regulated vehicles
- Operational simplicity: trading on traditional markets, with the same procedures as stocks and ETFs.
- Compliance: compliance with internal policies and supervisory requirements.
- Reputational risk management: standards of best execution, audit, and separation of roles.
Supply Concentration: Numbers, Effects, and Trade-offs
The weight of IBIT exceeds 3% of the circulating BTC supply. In a post-halving 2024 context, with scarcer new issuance, the aggregate demand of ETFs impacts the scarcity dynamics and price formation. The downside is an increasing concentration of tokens in a few vehicles, a sensitive issue for those advocating for a more widespread distribution of the asset.
Liquidity and price discovery: more depth but greater dependence on flows
The entry of regulated capital has expanded the volumes and, under normal conditions, improved the spreads. In this context, a growing share of activity passes through a few channels, with the risk that inflow and outflow of ETFs become primary drivers of volatility during stress phases.
- Pro: greater depth of the order book and more efficient price discovery (see also our guide on price discovery in crypto).
Cons: dependence on the flows of listed vehicles and risk of asset concentration.
Institutional portfolios: concrete advantages and risks
The main management firms, when they include BTC, do so with modest allocations (typically 1–2%) to maximize the benefits of diversification in the face of high volatility.
Advantages
- Regulated access to digital markets.
- Insured custody with professional providers (see also our guide on crypto custody).
- Potential decorrelation in the medium to long term.
Risks
- Concentration of supply among a few institutional holders.
- Greater correlation with traditional markets during stress phases.
- Operational risks related to massive flows and rebalancing algorithms.
Decentralization vs mediated access: the new balance
Bitcoin remains a decentralized network, but access through ETFs entrusts custody to a few centralized and regulated actors. It must be said that the compromise between practicality and cypherpunk principles is at the center of the debate: the more investors enter through institutional channels, the greater the need for transparency on custody, economic rights (not on-chain governance), and management of the vehicles.
Scenarios in the coming months
- Greater concentration: IBIT among the main single holders of BTC, with impact on the market microstructure.
- Regulatory clarity: new guidelines could unlock complementary products (e.g., covered-call on BTC or multi-asset indices with crypto).
- Hybrid model: decentralized base layer, centralized and supervised access for large capitals.
In summary
With over 662,600 BTC in its holdings as of June 10, 2025 (rising to about 750 thousand by mid-August), IBIT by BlackRock has transformed Bitcoin into an institutionalized asset class. Depth and liquidity are increasing, but so are the risks of concentration and dependence on ETF flows. The decisions of regulators and the management of vehicles in the coming months will determine their structural impact on the market and decentralization.
Source: https://en.cryptonomist.ch/2025/08/19/blackrock-over-3-of-bitcoin-supply-what-does-it-mean-for-the-market/