Bitcoin ETFs Lose $463 Million in a Week as Ether Funds Attract $197 Million

Outflows on 8–11 September broke a three-week streak of inflows into spot bitcoin ETFs, and the funds' assets fell below $100 billion. Meanwhile, capital is rotating into ether and altcoins.

In brief: Over four trading sessions from 8 to 11 September 2026, $462.73 million was withdrawn from US spot bitcoin ETFs — breaking a three-week inflow streak, the best of 2026. Total assets of the bitcoin funds fell below the psychological $100 billion mark, to $97 billion. At the same time, spot ether ETFs attracted $197.11 million and completed a fourth consecutive week of inflows, with assets of $16.3 billion — the highest since January. Data: SoSoValue, published 12 September.

Daily flows: bitcoin versus ether

Date	Spot BTC ETFs	Spot ETH ETFs
8 September	−$46.65 million	−$24.29 million
9 September	−$120.24 million	+$34.75 million
10 September	−$282.56 million	−$29.76 million
11 September	−$13.29 million	+$216.41 million
Total	−$462.73 million	+$197.11 million

The 10 September outflow of $282.56 million was the largest single-day figure since July. The mirror image on 11 September is also telling: on the day US inflation data came out and bitcoin was sliding toward $76,000, bitcoin funds lost almost nothing, while ether funds took in $216 million — the largest daily inflow of the week.

Where the capital is going: altcoin ETFs

The expansion of the exchange-traded fund lineup in 2026 has made the flow picture noticeably more fragmented. Over the same 8–11 September period:

Fund	Net flow
XRP ETFs	+$18.98 million
SOL ETFs	+$10.3 million
LINK ETFs	+$5.36 million
HBAR ETFs	+$1.25 million
DOT ETFs	+$0.66 million
HYPE ETFs	−$26.42 million

In total, altcoin funds were net positive, but the scale of these flows is an order of magnitude smaller than bitcoin's: even combined, they do not offset a single day of outflows from BTC ETFs. So this is not yet an "altcoin season" in the institutional segment, but selective diversification.

Why bitcoin is losing and ether is gaining

Three factors market participants point to.

De-risking ahead of the Fed. The market is awaiting the US Federal Reserve (the Fed) meeting on 16 September with a high probability of a rate hike — CME FedWatch estimates rose to roughly 70% last week. Institutional portfolios cut exposure to the most "beta-heavy" asset in advance; the same is visible in derivatives, where BTC open interest fell 13.5% in a week. More in the market overview.

Ether's relative strength. ETH is holding around $2,500, while BTC lost 3.4% over the week. Ether's share of market capitalization is 11.6% versus 58.8% for bitcoin; with comparable market dynamics, the smaller base gives ether a larger percentage response to inflows.

Profit-taking after a strong stretch. Over the previous three weeks, bitcoin ETFs collected around $3.8 billion, according to 2bitcoins — the best result of the year. After such a streak, a pullback in flows is ordinary mechanics, not in itself a trend reversal.

Context: a tough year for bitcoin ETFs

In the first half of 2026, around $5.4 billion was withdrawn from US spot bitcoin ETFs — the first negative half-year since the funds launched in January 2024. Summer and August inflows partly closed that hole: since the start of 2026, the cumulative flow total is around −$1 billion. Against the backdrop of recovery, the three-week inflow streak in late August and early September looked like a turn in sentiment, and the market took its interruption harder than the $463 million figure itself.

A separate factor this week is the expiry of IBIT options on 18 September worth around $5 billion. Large expiries on a fund derivative usually raise volatility and indirectly affect flows: market makers rebalance their hedges.

Corporate demand, meanwhile, has not gone anywhere: Strategy (MicroStrategy) holds around 845,000 BTC on its balance sheet, and stablecoin market capitalization is roughly $310 billion. Both figures are estimates by GBIG Holdings founder Rufat Abyasov as of 13 September 2026 (quoted by Finance Mail.ru).

How to read ETF flow data correctly

Competitors usually skip this section, and without it the numbers are easy to misread.

Net flow ≠ one-to-one buying or selling of coins. An outflow means redemption of fund shares; the actual sale of BTC by the issuer happens with a lag and depends on the mechanics of basket creation and redemption.
Data arrives with a T+1 delay. Friday's figures are published over the weekend or on Monday, so "fresh flows" always describe yesterday's market.
One day is not a signal. What matters are streaks: three to four weeks of one-directional flows, not a single $282 million outflow.
Look at AUM, not just flows. Fund assets also change because of revaluation: part of the drop below $100 billion in bitcoin ETFs came from the BTC price decline itself, not only from withdrawals.
Separate bitcoin from the other funds. With the expanded lineup, the aggregate "crypto ETF" line has stopped being informative — flows into BTC, ETH and altcoins are now moving in different directions.

What to watch next

The nearest fork in the road is the Fed decision on 16 September and the tone of the press conference. A resumption of inflows into bitcoin funds after the meeting would be a more convincing confirmation of demand than any technical price bounce: sustained spot demand, in CryptoQuant's assessment, is exactly what the market lacks right now.

The second storyline is whether ether can hold its inflow streak. A fifth consecutive week of positive flows with assets above $16 billion would mean the capital rotation from BTC to ETH is not a one-off episode. The technological backdrop is there: the network is preparing for the Glamsterdam upgrade, with the Sepolia testnet fork scheduled for 6 October.