
BlackRock accumulated more than $120 million worth of Bitcoin (BTC) through its iShares Bitcoin Trust (IBIT) over the latest trading week.
Data from spot Bitcoin ETF flows show the world’s largest asset manager recorded net inflows of approximately $120.6 million between September 14 and September 18.
The fund attracted $134.3 million on September 14, suffered outflows on September 15 and 16, then rebounded with inflows of $183.7 million and $108.4 million during the final two sessions of the week.

Bitcoin spot ETF ouflow/inflow. Source: CoinGlass
The weekly inflow came as the leading cryptocurrency reclaimed the $80,000 level after a turbulent period marked by rising Treasury yields, inflation concerns, and a Federal Reserve rate hike. Bitcoin traded above $80,500 on September 18, extending a recovery that followed heavy ETF redemptions earlier in the week.
ETF market swings
While BlackRock emerged as a net buyer, the broader spot Bitcoin ETF market experienced sharp swings throughout the week.
U.S. spot Bitcoin ETFs recorded inflows of $160 million on September 14 before posting consecutive outflows of $450.3 million and $296 million on September 15 and 16.
Sentiment improved afterward, with net inflows of $159.5 million on September 17 and another $433 million on September 18, driven largely by Fidelity and renewed demand across several funds.

Ethereum spot ETF ouflow/inflow. Source: CoinGlass
The latest activity highlights a market that remains highly sensitive to macroeconomic developments.
Despite the recent volatility, spot Bitcoin ETFs have accumulated approximately $54.7 billion in net inflows since their launch in January 2024 and now manage roughly $96.2 billion in assets.
September has been mixed for the sector, with ETFs recording more outflow days than inflow days so far this month, though strong buying sessions have offset much of the selling pressure.
A single trading day on September 3 brought more than $730 million in net inflows, one of the strongest sessions of the year.
Institutional demand has remained a key support for Bitcoin’s recovery. Earlier this month, U.S. spot Bitcoin ETFs attracted nearly $987 million in weekly inflows, extending a multi-week streak that brought in more than $3.8 billion of fresh capital.
Ethereum ETF outflows
Meanwhile, while BlackRock was a net buyer of Bitcoin during the week, its Ethereum (ETH) ETF products moved in the opposite direction.
In this vein, BlackRock’s ETHA and ETHB funds recorded a combined net outflow of about $49.1 million over the same five-session period. The divergence suggests institutional investors recently showed stronger demand for Bitcoin exposure than Ethereum exposure through regulated ETF products.
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