Key HighlightsSpot Bitcoin and Ethereum ETFs in the U.S. recorded $2.61 billion in combined inflows during a five-day trading periodBitcoin-focused funds captured $1.92 billion, representing approximately 73% of the totalEthereum ETFs brought in $697 million with positive flows across all five trading daysBlackRock’s products dominated both markets, securing roughly 79% of Friday’s aggregate inflowsBitcoin’s price surged approximately 18% over two days, pushing past the $76,000 markExchange-traded funds tracking spot Bitcoin and Ethereum in the United States achieved their most robust combined weekly performance since October 2025, attracting $2.61 billion in capital throughout the five trading days that concluded on August 21.This remarkable influx represented a complete reversal from the preceding week’s combined outflow of $391.96 million, marking a differential of approximately $3 billion.Bitcoin Products Dominate Weekly InflowsBitcoin-focused exchange-traded funds accumulated $1.92 billion throughout the week, with momentum accelerating daily. The sequence initiated with $297 million entering on August 17, advanced to $517 million by August 19, reached a weekly high of $606 million on August 20, before moderating to $307 million during the final session.ETFs bought $1,920,000,000 in $BTC this week.Biggest weekly inflow since October 2025. pic.twitter.com/c8rbuSmsRF— Ted (@TedPillows) August 22, 2026BlackRock’s iShares Bitcoin Trust emerged as the leading product throughout every session. During the August 21 trading day specifically, it absorbed $239 million, accounting for approximately 78% of that day’s aggregate inflows.The iShares Bitcoin Trust has accumulated $62.43 billion in cumulative net inflows since its inception. Fidelity’s competing product added $30 million during the same session, elevating its cumulative total to $10.18 billion.Collectively, all U.S. spot Bitcoin ETFs maintain $96.07 billion in net assets, representing 6.17% of Bitcoin’s aggregate market capitalization.The $1.92 billion weekly figure marks the strongest performance since October 2025, when these investment vehicles attracted $2.71 billion during one week and $3.24 billion in another.Ethereum Products Show Impressive MomentumEthereum-tracking ETFs accumulated $697 million throughout the identical five-day period, representing their strongest weekly showing in recent months. Daily capital inflows expanded from $30 million on August 17 to $221 million by August 20, concluding with $185 million on August 21.BULLISH: Ethereum crosses $2,500 for the first time since March after surging 30% in five days.$ETH is up another 9% today.It spent most of August stuck below $2,000.The Aug 19 move was a 20% single-day surge, its largest since May 2025.Spot ETH ETFs pulled in over $500… pic.twitter.com/Jh5sI21vTQ— Coin Bureau (@coinbureau) August 21, 2026BlackRock’s iShares Ethereum Trust commanded Friday’s trading session with $151 million in net inflows. Grayscale’s Ethereum Mini Trust secured second position with $11.5 million.Aggregate net assets held within Ether ETFs reached $14.30 billion by session close, equivalent to 4.85% of Ethereum’s total market capitalization.The weekly aggregate exceeded the entire July month’s performance, when Ether ETFs collectively gathered $365 million.Bitcoin’s market price advanced approximately 18% across two trading days, penetrating key resistance levels at $65,000, $70,000, and $75,000 before ultimately exceeding $76,000 on August 21. Ethereum similarly gained around 18% within a single 24-hour period, climbing above the $2,400 threshold.Nick Ruck, Director of Research at LVRG, observed that consistent inflows would necessitate additional confirmation before establishing a definitive long-term trend.Certain market participants are currently reallocating capital toward alternative cryptocurrencies. Bitcoin Cash appreciated 31% on August 21, while Ethena recorded a 27% increase. Bitcoin dominance maintained a position near 59.8%, with the Altcoin Season Index registering 33 out of 100.BlackRock accumulated a combined $390 million across both Bitcoin and Ethereum ETFs on Friday, representing approximately 79% of the day’s aggregate inflows spanning both asset categories.The post Bitcoin and Ethereum ETFs Capture $2.6 Billion in Strongest Week Since October appeared first on Blockonomi.