BlackRock’s iShares Bitcoin ETF (IBIT) has grown its assets under management (AUM) by almost 50% in less than 10 days amid Bitcoin’s (BTC) rally to new highs, according to the firm’s data updated on March 12.

IBIT has maintained its reign as the largest spot Bitcoin ETF out of the Newborn Nine — excluding the converted Grayscale GBTC ETF — since the US SEC approved them in January.

IBIT rivals MicroStrategy’s hoard

The IBIT has accumulated 203,754 BTC for investors in less than three months, marking it as the ETF with the highest Bitcoin holdings among the newly approved funds.

The amount puts it just behind MicroStrategy, which recently spent almost a billion dollars to grow its holdings to 205,000 BTC.

In comparison, Fidelity’s FBTC is the second-largest spot Bitcoin ETF with $9.2 billion in AUM. BlackRock and Fidelity together have garnered more than $17 billion in net inflows from investors.

Following the success of IBIT, BlackRock has shown interest in expanding Bitcoin exposure to its other funds and has applied for SEC approval. Additionally, BlackRock has extended its Bitcoin ETF offerings to Latin America in partnership with Brazil’s B3 stock exchange.

Strong inflows

Bitcoin ETFs overall experienced net inflows of $505.5 million on March 11, with IBIT leading at $562.9 million — representing a 0.12% increase in total assets.

Other ETFs, including Bitwise’s BITB, ARK Invest’s ARKB, and VanEck’s BRRR, also saw inflows, while Invesco’s BTCO reported outflows of $9.7 million. Meanwhile, Grayscale experienced the highest level of outflows since Feb. 29, with $494 million leaving the fund.

The net inflow of Bitcoin into ETFs was 7,009 BTC, with IBIT accounting for 7,805 BTC of the total. On the other hand, FBTC added 2,988 BTC, BITB 690 BTC, ARKB 180 BTC, and BRRR added 1,648 BTC.

Overall, the funds have experienced record performance since their launch, with daily volume exceeding $10 billion on some days.