BlackRock's iShares Bitcoin Trust (IBIT) has purchased an additional $128.33 million in Bitcoin amid sustained institutional demand for U.S. spot Bitcoin ETFs. IBIT has led inflows throughout the week, with on-chain data from Arkham indicating approximately $478.5 million in daily Bitcoin acquisitions by the fund.

According to crypto analyst Ash Crypto, the latest purchase totaled $128.33 million. Arkham tracking shows the transfers were executed in batches of roughly 250 to 300 BTC, bringing the total BTC held in IBIT's on-chain portfolio to approximately 742,000 BTC.

BREAKING: 🇺🇸 BlackRock ETF has bought $128,330,000 worth of Bitcoin. pic.twitter.com/1lsVZy4blV — Ash Crypto (@AshCrypto) August 7, 2026

Source: X post by Ash Crypto (@AshCrypto)

The purchases align with broader ETF flow data. United States spot Bitcoin ETFs recorded a combined $626 million in total inflows during the period, with IBIT accounting for 76% of that amount. The concentration of flows into BlackRock's fund underscores IBIT's dominant market position since the SEC approved spot Bitcoin ETFs in January 2024. BlackRock, the world's largest asset manager with over $10 trillion in assets under management, launched IBIT alongside competitors including Fidelity's FBTC and Bitwise's BITB, but IBIT has consistently captured the largest share of cumulative inflows across the spot Bitcoin ETF cohort.

BlackRock ETF Leads Institutional Bitcoin Demand

On-chain data from Arkham Intelligence suggests that BlackRock Inc.'s cryptocurrency portfolio has grown by more than $3.7 billion since early July, with indications that investors may be reallocating capital between Bitcoin and the firm's altcoin funds.

Arkham Intelligence data indicates that IBIT experienced a holding change of 3,710 BTC between July 1, 2026, when holdings stood at 743,190 BTC, and August 6, when holdings reached roughly 749,480 BTC. During the same period, BlackRock's iShares Ethereum Trust ETF (ETHA) recorded an increase of 196,340 Ethereum (ETH). ETHA launched in July 2024 following the SEC's approval of spot Ethereum ETFs, expanding BlackRock's regulated crypto product lineup beyond Bitcoin.

Spot Bitcoin ETFs provide Bitcoin exposure through standard brokerage accounts, eliminating the need for investors to manage private keys or wallets. BlackRock states that IBIT simplifies the operational and custody complexities associated with direct Bitcoin holding. The fund's regulated custody structure and established market infrastructure may appeal to investors seeking more straightforward Bitcoin exposure. The ability to access Bitcoin through conventional brokerage and retirement accounts has been a key factor broadening participation beyond direct crypto holders.

ETF Flow Trends in Focus

Market participants will monitor whether IBIT continues its daily purchase pattern and whether other Bitcoin ETFs sustain their inflow trajectory. Continued ETF creations could contribute to Bitcoin demand, while reduced flows would lessen that effect. Analysts will also track on-chain ETF holdings, creations, and transfers for signals regarding institutional engagement. Flow data from Farside Investors and other ETF trackers has shown that periods of sustained net inflows have often corresponded with increased Bitcoin demand from the largest ETF issuers, while outflow streaks have typically been led by Grayscale's converted GBTC fund rather than newer entrants like IBIT and FBTC.

The latest data points to concentration in the BlackRock ETF specifically, rather than broadly distributed activity across all market segments. The reported 742,000 BTC figure reflects Arkham's tracked estimate. Institutional Bitcoin exposure continues to expand through regulated vehicles, and subsequent BlackRock ETF flows will be a key indicator of whether current momentum is maintained.

Arkham Intelligence data referenced in this report is available at Arkham Explorer — BlackRock.