After a strong August rally, where the Spot Bitcoin [BTC] ETFs recorded $3.52 billion in inflows in a month, the September effect seems to be kicking in. In the past week, from 8th to 11th September, BTC ETFs recorded outflows worth $462.73 million.
The week started on a negative note with a cumulative net outflow reaching $46.6 million. This was mainly because of Fidelity’s $17.1 million, Invesco’s $4.7 million, and particularly Grayscale GBTC, which saw a huge $65.5M outflow.
Bitcoin ETFs’ weekly flow analysis
On 9th September, selling pressure became stronger with BlackRock experiencing a $19.5 million outflow, ARKB losing $78.0 million, and Grayscale GBTC losing another $27.2 million, bringing the net outflows to $120.2 million.
The situation deteriorated further on 10th September, which was the worst day of the week with $282.7 million in net outflow. However, on 11th September, things were a little better as the total outflows totaled just $13.2 million.
Across these four days, the ETFs collectively experienced approximately $462.7 million of cumulative net outflows, with Ark Invest’s ARKB and Grayscale GBTC being the most significant sources of selling pressure.
This happened at the same time the price of Bitcoin fell from around $79K to $77,324.76 at press time after a drop of 2.9% in the past week.
Ethereum ETFs took a different route
Though Spot Ethereum [ETH] ETFs usually follow a very similar pattern to BTC ETFs, this time things were a little different. On 8th September, activity was relatively weak, as the total net outflow reached $24.3 million.
On 9th September, the trend reversed decisively, with the products recording a total net inflow of $34.7 million. But on 10th September, selling pressure returned.
The most significant change came on 11th September, when the Ethereum ETFs recorded a strong $216.4 million in net inflow, the largest positive daily total in the past week.
BlackRock ETHA was the main contributor with a huge $148.8 million inflow, followed by BlackRock ETHB at $18.3 million.
Other altcoins showed mixed patterns
Needless to say, other altcoins also saw mixed flow patterns, with the Solana [SOL] ETF recording $10.30 million in inflows in the past week.
The main contributor of these flows was Bitwise’s BSOL. On the other hand, XRP ETF recorded $0.00 in flows in the past week as per SoSo Value data. Whereas Hyperliquid [HYPE] ETFs recorded $26.42 million in net outflows during the same period.
Bitcoin continues to stand strong
Yet despite a comparatively strong performance in terms of inflows and outflows streak, the altcoin index standing at 40 still suggests that BTC continues to rule the throne.
At the same time the Crypto Fear and Greed Index lying in the ‘Greed’ zone at 63 at press time further suggests that the investors are bullish and this might just be a temporary slowdown.
This is because the first week of September was also strong in terms of inflows thanks to the changing macroeconomic environment, particularly expectations around U.S. monetary policy.
Final Summary
- Spot Bitcoin ETFs saw weekly outflows worth $462.73 million in the past week as the price dropped.
- The other altcoin ETFs saw a mix of inflows and outflows during the same period.

