BlackRock, the world's largest asset manager, has conducted significant cryptocurrency transactions in early September 2025, moving approximately $297 million worth of Ethereum and Bitcoin to Coinbase Prime. According to on-chain data from Lookonchain and Arkham, the firm sold 44,774 ETH ($195.29 million) and 900 BTC ($101.67 million) on September 9th.
This activity represents part of BlackRock's ongoing portfolio management strategy for its massive crypto holdings, which total approximately $99 billion across 746,000 BTC ($82.4 billion) and 3.762 million ETH ($16.5 billion). The recent transactions follow a pattern of rebalancing between the two major cryptocurrencies. On September 3rd, BlackRock sold $151.4 million in ETH while buying $290 million in BTC, with these moves directly correlating with ETF flow data showing corresponding outflows from its Ethereum ETF and inflows to its Bitcoin ETF.
Despite the substantial selling pressure, both cryptocurrencies have maintained relative stability near multi-month highs. Bitcoin was trading around $112,000 and Ethereum near $4,350 as of September 9th, demonstrating the market's ability to absorb these large institutional moves. Historical data shows that previous BlackRock rebalancing events caused brief price declines (3.3% for ETH and 2.1% for BTC on September 3rd), but prices subsequently recovered.