BlackRock Adds $291M to Crypto Holdings in Four Days, Buys Bitcoin and Cuts Ethereum

BlackRock Inc. (NYSE: BLK) expanded its cryptocurrency exposure by more than $291 million over four exchange-trading days through October 6, even as the broader crypto market moved sideways in the first week of October 2026. Data reviewed by Finbold from SoSoValue on October 7 show BlackRock's crypto portfolio rose $291.7 million over the period. The firm's iShares Bitcoin Trust (IBIT) bought $545.57 million worth of Bitcoin (BTC) between October 1 and 6, lifting IBIT's net assets to $9.62 billion. By contrast, BlackRock's iShares Ethereum Trust ETF (ETHA) reduced its Ethereum (ETH) exposure by $253.87 million across the same four exchange-trading days. On October 6, ETHA's net assets fell about $201.89 million, its largest single-day decline since January 21. BlackRock's website shows ETHA holds 3,656,389.78 ETH, valued at more than $9.8 billion. Market reaction tracked the flows. After the manager accumulated more than 4,000 BTC in four days, Bitcoin gained about 1.13% to roughly $83,960 at the time of writing, for an estimated market capitalization near $1.7 trillion. Ethereum moved in the opposite direction, sliding more than 3% to retest $2,597, with a market cap of $314.7 billion. Over the last 24 hours, ETH trading volume jumped more than 70% to $18.2 billion, according to CoinMarketCap metrics. Overall, BlackRock's Bitcoin and Ethereum activity over the past four exchange-trading days coincided with their price performance over the last week.