BlackRock's income and bond-focused funds have incorporated shares of the asset manager's own spot Bitcoin exchange-traded fund (ETF) during the first quarter, as indicated by regulatory filings. The Strategic Income Opportunities Fund (BSIIX) invested $3.56 million in iShares Bitcoin Trust (IBIT), while the Strategic Global Bond Fund (MAWIX) allocated $485,000 for the same purpose, based on Securities and Exchange Commission filings from May 28. These investments represent a fraction of BSIIX and MAWIX's overall portfolios, valued at $37.4 billion and $776.4 million, respectively. IBIT, currently holding $19.61 billion worth of Bitcoin according to BlackRock data from May 24, trails only behind Grayscale Bitcoin Trust (GBTC) in terms of holdings. CoinGecko reports that spot Bitcoin ETFs globally possess over 1 million Bitcoin, totaling over $68 billion, representing approximately 5.10% of the circulating supply of over 19.7 million BTC. Moreover, more than 600 U.S. investment firms have invested in spot Bitcoin ETFs since their launch in January, as per recent SEC filings. Notable firms, including Morgan Stanley, JPMorgan, Wells Fargo, and hedge funds like Millennium Management, have been active in purchasing Bitcoin funds. Millennium stands as the largest spot Bitcoin ETF accumulator, with investments totaling $1.9 billion, including significant amounts in IBIT and the Fidelity Wise Origin Bitcoin Fund (FBTC). Additionally, on May 23, BlackRock was among the eight firms to have its spot Ether ETF bid approved in the U.S., with the SEC awaiting approval of the firm's Form S-1 filings for the products to commence trading.