BlackRock added 11,098 BTC, worth roughly $852 million, and 132,769 ETH, worth about $316 million, to its holdings over a two-day span this week, according to on-chain tracking. The buying lines up with a broader institutional wave: spot Bitcoin ETFs recorded $606 million in net inflows on August 20 alone, marking four consecutive days of net inflows across the category.
The pace continued into the following session. Aggregate data for August 21 showed spot Bitcoin ETFs pulling in 8,879 BTC (about $684 million) in a single day and 22,043 BTC (roughly $1.7 billion) over the trailing week, while spot Ethereum ETFs added 86,701 ETH (about $207 million) that day and 219,254 ETH (around $524 million) over seven days.
BlackRock's outsized share of the flow
BlackRock's IBIT has been capturing a disproportionate share of that institutional demand throughout August, a pattern consistent with the thinning overhead supply on Bitcoin's order book that has been narrowing the path toward higher prices. The fund's dominance reflects BlackRock's distribution network and its head start in marketing spot crypto exposure to institutional allocators who might otherwise sit out direct token custody entirely.
Retail-facing platforms are buying too
The institutional wave isn't confined to BlackRock. Separate on-chain tracking showed clients buying $503.01 million worth of BTC and $173.3 million worth of ETH through a major brokerage platform in the same window, alongside a smaller $9.9 million purchase of XRP — evidence that the demand driving ETF inflows is also showing up directly in retail brokerage order flow rather than one or two large allocators alone.
All of this activity is verifiable in real time; Arkham Intelligence's on-chain explorer for BlackRock's tracked wallets shows the entity's holdings updating as purchases settle.
Related: Bitcoin ETFs Post Biggest Inflow Since May, BlackRock Grabs 83%
What sustained inflows would mean next
Four straight days of net ETF inflows, layered on top of direct on-chain accumulation by BlackRock, suggests institutional demand is broadening rather than concentrating in a single fund. Whether that demand holds through any pullback in spot prices will be the next test of how durable this week's buying really is.
