US spot bitcoin ETFs have recently experienced a notable surge in net inflows, with BlackRock’s iShares Bitcoin Trust (IBIT) emerging as a primary driver of this positive momentum. Data indicates that on a specific Monday, these ETFs collectively attracted $31.1 million, with IBIT alone accounting for $55 million. This significant contribution from IBIT, while other funds in the category saw net outflows, highlights its prominent position in the market.
Over the week ending September 25, 2026, the trend of positive inflows continued, with US spot bitcoin ETFs gathering a total of $2.4 billion. BlackRock’s IBIT was a major contributor, securing approximately $1.2 billion of these inflows, marking its second-largest weekly total since October 2025. Fidelity’s FBTC also saw substantial inflows, managing about $702 million during the same week, though this was roughly 40% less than BlackRock’s attraction.
The asset base for IBIT has grown substantially, reaching nearly $67 billion. This growth reflects a broader recovery in investor sentiment towards US spot bitcoin ETFs. By mid-July, year-to-date flows for the category were approximately negative $5.8 billion. However, by late September, these flows had flipped to a positive $934 million, representing a swing of nearly $6.7 billion in a matter of weeks. Lifetime cumulative inflows for the entire US spot bitcoin ETF category reached about $57.6 billion by late September, with net assets approaching $108 billion.
In comparison, spot ether ETFs have experienced a more varied performance. On the same Monday that saw bitcoin ETFs attract inflows, spot ether ETFs attracted $17.1 million. For the week ending September 25, spot ether ETFs accumulated roughly $690 million, following a $140 million outflow in the preceding week.
Analysis suggests that IBIT’s market position may be reinforced by its liquidity and trading characteristics. Reports indicate that IBIT’s bid-ask spreads and trading volumes are consistently tighter and higher than those of its competitors. This greater liquidity can attract more capital, potentially creating a self-reinforcing cycle.
Further examination of inflow patterns reveals a potential concentration of demand. One Monday during the late-September stretch saw nearly $999 million flow into bitcoin ETFs in a single day, which ranked as the ninth-largest single-day total since the products launched. However, the data also suggests a tapering of enthusiasm throughout the week, with inflows dominating at the start and diminishing in subsequent days. This pattern may hint at episodic rather than steady demand.
It is important to note that specific Monday dates for daily inflow figures were not provided, and the exact date for the week ending September 25, 2026, is not specified beyond the year. These details are based on data reported for the period ending September 25, 2026.
Why This Matters
The materials describe a narrow update: On a specific Monday, US spot bitcoin ETFs saw $31. The specific Monday dates for the daily inflow figures are not provided.
Broader Context
Source materials place the factual news in this context: US spot bitcoin ETFs pulled in $31.1 million in net inflows on Monday, with BlackRock’s iShares Bitcoin Trust (IBIT) accounting for the lion’s share at $55 million. That means other funds in the category were net sellers on the day, making IBIT’s gravitational pull on capital even more conspicuous.
