US spot Bitcoin and Ethereum exchange-traded funds pulled in a combined $492 million in net inflows on August 21, extending a five-day run of positive sessions for both groups, according to public flow data from Farside Investors. Bitcoin funds took the larger share at $307 million, while the Ethereum funds added $185 million.
BlackRock leads both tables
BlackRock was the top driver in each category. Its spot Bitcoin fund, IBIT, recorded $239.3 million on the day, and its spot Ethereum fund, ETHA, brought in $151 million. That put BlackRock at the front of both asset groups, reinforcing its position as the dominant gateway for institutional money moving into crypto ETFs.
Weekly totals cross $2.6B
Looking at the full week, Bitcoin ETFs added $1.92 billion and Ethereum ETFs added $697 million, for a combined $2.6 billion across the two groups. Those are net-flow figures, not cumulative assets under management, so they reflect new money coming in rather than market movement.
Five straight positive sessions suggest investors were adding exposure steadily, not just making a one-off allocation. But flow streaks can end quickly, and the next test is whether the money keeps coming as price volatility returns.
What strong ETH flows mean
The sustained interest in Ethereum ETFs could give a tailwind to DeFi, staking, tokenization, and smart-contract narratives, since those sectors depend on the same network. That is a meaningful signal for a market that often watches ETH flows as a proxy for developer activity and decentralized app demand.
The data comes from Farside Investors, which tracks daily and weekly net flows. Both fund groups have now held a positive streak for five straight sessions.
