October 21, 2026 – BlackRock’s bitcoin fund drew $665.2m on Monday, its best session since October 2025. Fidelity and Grayscale lost money the same day, and ether funds extended a four-day slide.
In Summary
BlackRock’s spot bitcoin ETF took in $665.2m on 19 October, its largest single day since 7 October 2025 on a check of the full daily series.
Fidelity shed $83.6m and Grayscale $54.9m the same day, so the whole group netted $526.7m.
The inflow still ranks outside the fund’s five biggest days, the largest of which was $1.12bn in November 2024.
US spot ether ETFs lost $103.3m on Monday, a fourth straight losing session totalling $362.8m, before a small $6.9m intake on Tuesday.
BlackRock reports fund net assets of $65.70bn on 19 October, so Monday’s intake equals 1.01 percent of the fund on Catenaa calculations.
The largest bitcoin ETF had its best day in a year. BlackRock’s fund took in $665.2m on Monday 19 October. No single day had beaten that since 7 October 2025.
Rivals did not share the lift. Two other funds lost money, so the whole group netted $526.7m.
The timing was not random. Equities had just steadied after a bruising week, and risk appetite returned across the board.
How big the bitcoin ETF day really was
Flow data for 19 October shows $665.2m into the BlackRock fund. Meanwhile Fidelity shed $83.6m and Grayscale lost $54.9m.
So one fund drew more than the sector kept. Its intake ran to 1.26 times the group net, on Catenaa sums.
Concentration is the real story. One manager now drives the sector tally, so a single desk can swing the daily headline.
Yet context trims the drama. Checking the full daily series, Monday ranks outside the fund’s five biggest days.
The record still stands well clear. November 2024 brought $1.12bn in a single session, roughly 1.7 times Monday, on Catenaa sums.
A week of exits came first
The run-up was weak. Three of the five prior sessions saw money leave the fund, including $110.9m on 14 October.
Then equities steadied and the mood turned. Therefore Monday reads as a snap-back rather than a trend.
Ether funds moved the other way
The split across assets was stark. US spot ether ETFs lost $103.3m on Monday, a fourth straight losing session.
Those four days drained $362.8m, on Catenaa sums. However Tuesday broke the run with a small $6.9m intake.
So capital rotated rather than arrived. Investors trimmed one coin while adding to the other, which fits a cautious risk mood.
Scale sharpens that contrast. The ether outflow looks small in dollars, yet it ran the opposite way on the very same day.
What it means for the fund
Size puts the day in proportion. BlackRock reports net assets of $65.70bn on 19 October. So Monday’s intake equals 1.01 percent of the fund, on Catenaa sums.
The coin itself helped. Bitcoin closed 20 October at $82,936.10, up 1.76 percent from the 16 October close, on Catenaa sums.
Fees stay low by fund standards. The sponsor charges 0.25 percent a year, which helps explain why flows cluster here.
Age helps too. The fund opened in January 2024, so it carries nearly three years of trading history and deep daily volume.
Those two traits compound. Cheap access and deep volume draw the largest tickets, which in turn deepens the volume further.
Still, one Monday settles nothing. The fund trades on Nasdaq, and flows there have swung hard all month.
What to watch from here
Three things matter next. First, whether inflows hold for a full week rather than a single session. Second, whether rival funds stop bleeding.
Third comes the ether side. A steady return there would signal broad risk appetite, not just a rotation into the largest coin.
For now the read is cautious. Money came back quickly, yet it went almost entirely to one fund and one coin.
