BlackRock’s IBIT Leads Bitcoin ETF Surge with $4.09B in Inflows Over 10 Days

BlackRock’s iShares Bitcoin Trust (IBIT) has firmly established itself as the frontrunner in the U.S. spot Bitcoin ETF market, accounting for the lion’s share of a staggering 10-day inflow streak totaling $4.26 billion.

According to data, IBIT alone pulled in $481 million on May 28—making it the only ETF in the category to register net inflows that day. In stark contrast, Ark Invest’s ARKB and Fidelity’s FBTC reported outflows of $34.3 million and $14 million, respectively, while other funds remained flat.

This streak cements IBIT’s dominance: the fund has contributed $4.09 billion—or 96%—of the total net inflows during this 10-day period. Since its launch in January 2024, IBIT has amassed $49 billion in total inflows, even outpacing the entire market’s $45.6 billion cumulative inflows. This figure significantly overshadows the $23.1 billion in net outflows from Grayscale’s higher-fee GBTC fund.

Notably, IBIT has now maintained 33 consecutive trading days without a single net outflow since April 9, despite experiencing three days with zero flow. Over this time, the fund has drawn in $9.31 billion and reached $72 billion in assets under management (AUM), placing it among the largest ETFs across all categories.

“Another nearly $500 million into iShares Bitcoin ETF… Starting to get ridiculous,” commented Nate Geraci, President of The ETF Store. “IBIT is comfortably in the top five ETFs by inflows this year—out of more than 4,200 funds.”

Bloomberg Senior ETF Analyst Eric Balchunas echoed this sentiment, noting that IBIT now ranks 23rd in overall ETF size.

“Absolutely bonkers for a one-year-old,” he said. “The next youngest ETF in the top 25 is 12 years old.”

The wider U.S. spot Bitcoin ETF market is also experiencing heightened activity, with over $25 billion in trading volume last week as Bitcoin hit a record high of $112,000. As of now, Bitcoin trades at around $108,492. On May 28 alone, spot Bitcoin ETFs saw $3.4 billion in volume, with IBIT responsible for $2.6 billion—nearly 80% of the day’s total.

Meanwhile, spot Ethereum ETFs are quietly gaining momentum. The category recorded $84.9 million in net inflows on May 28, led by BlackRock’s ETHA with $52.7 million. Other participants included Fidelity’s FETH ($25.7 million), Grayscale’s ETH ($4.9 million), and Invesco’s QETH ($1.6 million). Trading volume for Ethereum ETFs hit $446.9 million, marking the eighth straight day of inflows, now totaling $394.1 million.