US spot Ethereum ETFs posted a net outflow of $2.81 million on Sept. 29, ending a seven-day inflow streak that had added roughly $851 million since Sept. 18, according to SoSoValue data. Bitcoin funds kept buying the same day, pulling in $66.2 million in net inflows, more than double the $31 million they took in on Sept. 28. The two largest crypto ETF groups are now moving in opposite directions for the first time in over a week.
The split lands on the same day Ethereum crossed another marker: Tom Lee’s Bitmine bought another 17,362 ETH for about $47 million, lifting its treasury past 6 million tokens, or 4.9% of circulating supply. Institutional demand through ETFs and corporate treasury buying are pointing different ways, which is unusual this late in a recovery and worth unpacking session by session.
How the streak unfolded
The seven-day run peaked early. The funds drew $269.98 million on Sept. 21, their strongest single session of the stretch, then eased across most of the following sessions and slipped to $17.1 million by Sept. 28 before flipping negative. Weekly figures show how strong the run was at its height: the funds added $689.88 million in the week ending Sept. 25, their biggest week since late August, with BlackRock’s ETHA leading at $326.2 million.
That weekly total completely reversed the picture from the week before, when Ether funds had shed roughly $140 million. The reversal coincided with ETH holding the $2,600 level and with a burst of staking-related activity across the network, including a large entry queue that formed after SEC staff published FAQs in late September clarifying that pure staking receipt tokens for digital commodities such as Ether are not treated as securities offerings.
Bitcoin’s flows tell the other half of the story. BlackRock’s iShares Bitcoin Trust (IBIT) led all funds with $51.1 million in fresh capital on Sept. 29, accounting for more than three quarters of the day’s total. Bitcoin ETF inflows have now run positive for multiple sessions even as the price stalls near $83,000, down from an eight-month high near $87,400 hit earlier in the week.
| Fund group | Sept. 28 flow | Sept. 29 flow |
|---|---|---|
| US spot Bitcoin ETFs | +$31 million | +$66.2 million |
| US spot Ethereum ETFs | +$17.1 million | -$2.81 million |
Price action adds pressure
Ethereum traded near $2,680 on Tuesday, up modestly on the day but well below the local peak near $2,805 it printed last week. Bitcoin slipped back to $83,300 after touching $87,374, and on-chain data shows the rally lost steam even as sentiment indicators stayed bullish. CryptoQuant’s Bull Score hit 90, a reading historically associated with strong demand, while spot demand contracted by an estimated 170,000 BTC over 30 days.
That combination, bullish sentiment scores against shrinking spot demand, has preceded choppy stretches in past cycles. Traders are also watching macro data due this week, including the PCE inflation report, which has kept risk appetite in check across both crypto and equities. Derivatives positioning has thinned as well, with long liquidations totaling $392 million across the market as price pulled back below $84,000.
Why the divergence matters
ETF flows are the cleanest read on institutional demand because issuers must buy or sell the underlying coins to match share creations and redemptions. A $2.81 million outflow is small in absolute terms, roughly a rounding error against the $851 million that preceded it, but the direction change matters for momentum traders who treat streaks as signals and for allocators who rebalance on weekly flow reports.
The Bitcoin side of the split is harder to dismiss. IBIT alone took in more on Sept. 29 than all Ethereum funds combined had drawn on any day of their streak after the first one. If the pattern holds through the week, it would suggest institutions rotating back toward the larger, more liquid asset ahead of the inflation print rather than a broad retreat from crypto exposure altogether.
There is a precedent for reading too much into single-day flips. Ether funds posted a $140 million outflow week in mid-September, then followed it with their best week since August. Whipsaw in both directions has been the norm since the spot funds launched, and neither the bulls nor the bears have managed a sustained edge in the flow data for more than a few weeks at a time.
The upgrade overhang
One complication for the Ethereum narrative is the upcoming Glamsterdam upgrade. Developers scheduled the Sepolia testnet activation for Oct. 6, introducing enshrined proposer-builder separation and block-level access lists, two changes aimed at improving block construction efficiency and transaction ordering. Upgrades have historically produced volatility around their dates, and some allocators reduce exposure into them, then buy back after the fork completes without incident.
Mainnet timing for Glamsterdam has not been finalized and will depend on how the Sepolia test goes. If the testnet activation slips, the uncertainty window extends, which is rarely helpful for flows.
Neither flow figure changes the structural picture. Both fund groups remain net positive over the past month, and cumulative Ether ETF flows since launch remain well ahead of the outflow days. But the week’s flow data will show whether Sept. 29 was a one-day pause or the start of a rotation, and the PCE report due Friday is likely to decide which. A hot print would pressure both fund groups; an in-line one could restart the Ether streak as quickly as it ended.