According to documents filed with the U.S. Securities and Exchange Commission (SEC) on May 28, two funds under asset management giant BlackRock have included their own Bitcoin spot ETFs in their portfolios.

The documents show that the "BlackRock Strategic Income Opportunities Fund (BSIIX)" purchased $3.56 million worth of "iShares Bitcoin Trust (IBIT)" in the first quarter of this year; while the "BlackRock Strategic Global Bond Fund (MAWIX)" bought $485,000 of IBIT.

It is worth noting that the IBIT holdings of both funds only account for a small part of their respective portfolios. BSIIX's portfolio is currently worth $37.4 billion; MAWIX is worth $776.4 million.

According to data updated by BlackRock on May 28, IBIT's asset management scale (AUM) has exceeded $19.58 billion, and is expected to replace Grayscale's GBTC to become the largest Bitcoin spot ETF in the United States, which currently holds $19.75 billion in Bitcoin.

Bloomberg ETF analyst Eric Balchunas pointed out earlier this month that more than 400 institutions have invested in BlackRock's Bitcoin spot ETF so far this year, which is "incredible #贝莱德IBIT比特币持有量反超灰度GBTC $BTC $ETH $SOL