A substantial capital injection on the closing trading day of the prior week helped U.S. spot bitcoin (BTC) exchange-traded funds avoid a second consecutive negative week. Conversely, ether (ETH) investment vehicles lacked the same luck, concluding a four-week period of continuous inflows.
Market participants contributed $433 million to the publicly listed bitcoin instruments on Friday, yielding a total weekly net inflow of $6.2 million for the week concluding on Sept. 18, based on The Block’s evaluation of SoSoValue data. This net addition is relatively small, yet significant compared to the $462.7 million in withdrawals the funds experienced the preceding week.
Meanwhile, spot ether ETFs recorded a weekly net outflow of $140 million despite attracting $143.8 million on Friday. This outcome halted a run of four consecutive positive weeks during which the instruments accumulated a combined $1.94 billion.
Fidelity’s FBTC Drives Friday’s Recovery
Bitcoin ETFs successfully offset a major deficit generated by redemptions on Tuesday and Wednesday. Monday’s $160 million intake was succeeded by outflows of $450.3 million on Tuesday and $296 million on Wednesday. Even after taking in $159.5 million on Thursday, the funds remained down by $426.8 million for the week.
Friday’s purchasing activity erased that shortfall with very little margin to spare. The $433 million in daily inflows marked the largest single-day total for the products since Sept. 3, when they brought in $730.9 million.
Fidelity’s FBTC, the second-largest product of its kind based on assets under management (AUM) and trading turnover according to The Block’s figures, contributed $310.7 million to Friday’s aggregate, while BlackRock’s IBIT added $108.4 million. Products from Bitwise, VanEck, and the Ark alongside 21Shares partnership secured smaller relative volumes.
Over the entire week, however, IBIT pulled in $120.7 million, outperforming FBTC’s $79.9 million. The remaining bitcoin funds collectively shed approximately $194.4 million, keeping the sector barely in positive territory with a net inflow of just $6.2 million.
Bitcoin ETFs continue to sit down by approximately $1.45 billion in net flows for the year. Their overall historical inflows since inception rest at $55.16 billion, while net assets reached $102.53 billion as of Friday.
Bloomberg ETF analyst Eric Balchunas highlighted the endurance of bitcoin ETF investors in a Thursday post on X, pointing out that aggregate inflows stayed near $55 billion after peaking close to $63 billion. He characterized their holding power as “incredible intestinal fortitude from the Boomers given they saw a 50% drawdown,” while mentioning that rising equity markets may have assisted investors in maintaining their positions.
Ether Funds Snap Four-Week Inflow Streak
Regarding ether ETFs, three consecutive days of negative flows from Tuesday through Thursday, which drained $404.8 million, resulted in the conclusion of the products’ four-week inflow streak.
Capital allocations to these funds on Monday and Friday fell short of reversing those deficits. BlackRock’s ETHA secured $114.3 million on Friday but finished the week showing $56.1 million in net withdrawals. Fidelity’s FETH also closed the week lower, shedding $25.8 million despite a $26.2 million addition on Friday, according to The Block’s analysis of SoSoValue data.
This weekly outflow represented the first decline for ether ETFs since the week ending Aug. 14. Nevertheless, the products maintain a positive year-to-date standing, with roughly $922 million in net inflows. They maintained $16.72 billion in net assets as of Friday, compared to $13.25 billion in cumulative inflows since their launch.
Trading activity expanded across both sectors. Bitcoin ETF turnover climbed to $16.17 billion from the previous week’s $8.77 billion, whereas ether ETF turnover increased to $6.82 billion from $5.14 billion. Last week also featured an additional trading session, as the preceding week’s trading days were limited to four due to Labor Day.
Originally published at https://www.theblock.co/news/markets/2026-09-19-bitcoin-etfs-eke-out-positive-week-with-433-million-friday-inflow-as-ether-funds-snap-four-week-inflow-streak-415871.
