1. Bitcoin (BTC)
• As of August 13, 2025, the iShares Bitcoin Trust (IBIT) fund associated with BlackRock owns approximately 744,540 BTC, which constitutes about 3.545% of the total Bitcoin supply (21 million) and is valued at around $90.6 billion  .
• Previously, as of June 10, 2025, IBIT held over 662,500 BTC, valued at approximately $72.4 billion, which accounted for over 3% of the total BTC supply .
• In spring 2025, estimates varied — for example, around 567,000 BTC (~$47.8 billion) , or approximately 696,000–700,000 BTC according to Arkham/Reddit/Yahoo .
Conclusion:
BlackRock, through the IBIT fund, effectively controls hundreds of thousands of BTC — according to the latest information — about 744,540 bitcoins.
2. Ethereum (ETH)
• According to information as of August 4, 2025, BlackRock owns cryptocurrency Ethereum worth approximately $11 billion .
• The specific amount of ETH is not indicated, but it highlights significant presence in Ethereum assets.
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3. Other crypto-assets
• BlackRock has a minimal stake in the MicroStrategy fund, one of the largest holders of BTC: their stake is about 5.53%, which is equivalent to approximately 6,600 BTC, amounting to over $300 million .
• Additionally, in the first quarter of 2025:
• BlackRock had $5.4 billion in shares of companies related to Bitcoin (e.g., MicroStrategy shares) ;
• Over $1.02 billion invested in shares of mining companies (Riot Platforms, Marathon Digital, etc.) ;
• Approximately $279 million — in Bitcoin-based ETFs and trusts, including about $274 million in their own iShares Bitcoin Trust .
• Also, BlackRock is actively developing tokenized assets, for example:
• BUIDL — a tokenized money market fund worth around $3 billion ;
• Partnership with Securitize — over $2.8 billion issued in BUIDL, as well as tokenized funds Exodus, Apollo, etc. .