U.S. Bitcoin ETFs Rebound With $2.95 Billion Monthly Inflows After Senate Crypto Vote Shock

A sharp reversal in institutional capital flows has pushed U.S. spot Bitcoin exchange-traded funds back into a sustained accumulation phase, erasing the damage from a mid-September legislative shock that briefly spooked digital asset markets.

Bitcoin ETFs recorded $2.95 billion in net inflows over the past 30 days, extending their current streak of positive daily flows to eight consecutive trading sessions as of Sept. 28, according to data tracked by SoSoValue. The rebound follows one of the most severe single-day outflow events of the year, triggered directly by congressional gridlock over cryptocurrency market structure legislation.

The catalyst for the September sell-off was the failure of the Clarity Act in the U.S. Senate on Sept. 15. The bill, designed to establish a comprehensive regulatory framework dividing oversight between the Securities and Exchange Commission and the Commodity Futures Trading Commission, fell one vote short of the 60-vote threshold needed to advance, losing 49-50. Institutional investors reacted immediately. Bitcoin funds shed $450.4 million that day—their largest single-day withdrawal since June 24—while Ethereum ETFs simultaneously bled $142.3 million. For the week ending Sept. 15, Bitcoin ETFs managed just $6.2 million in net additions, marking their weakest weekly performance in 141 weeks.

Market mechanics shifted dramatically within 48 hours. By Sept. 17, buyers returned aggressively. A surge of nearly $1 billion in net inflows on Sept. 21 marked the strongest single day for the products since October 2025, followed by another $715 million on Sept. 22. While momentum gradually normalized through the rest of the week—pulling in $347 million, $191 million, and $134 million on consecutive days—the weekly total reached approximately $2.4 billion, the highest volume since last autumn.

This renewed buying pressure carried immediate consequences for underlying asset pricing. Bitcoin climbed back above $84,000 by late September, crossing a critical technical threshold: the estimated average cost basis of $81,722 for all spot ETF holders. Returning above this level means the typical fund investor moved back into profitability for the first time since January, reducing the likelihood of forced selling or panic redemptions that often compound drawdowns when prices fall below aggregate entry points.

BlackRock’s IBIT continues to anchor the sector’s inflow profile. On Sept. 28, the fund absorbed $54.84 million, offsetting persistent structural outflows from legacy products. Grayscale’s GBTC lost $23.19 million on the same day, while Fidelity’s FBTC saw $10.90 million in withdrawals. GBTC’s ongoing bleed reflects its higher fee structure relative to newer competitors; launched initially as a private trust before converting to a spot ETF in early 2024, it still carries expenses that prompt long-term holders to rotate into cheaper vehicles like IBIT or FBTC.

The current eight-day streak approaches but does not yet surpass the summer peak. A nine-day run ended on Aug. 28 after Federal Reserve Chair Kevin Warsh delivered remarks at the Jackson Hole economic symposium, triggering $201.9 million in outflows as traders rapidly repriced interest rate expectations. Spot crypto ETFs remain highly sensitive to macroeconomic signals, particularly Fed policy guidance, because institutional allocators treat digital assets as high-beta risk instruments heavily influenced by liquidity conditions.

Capital is also rotating deeper into altcoin investment vehicles, reflecting broader SEC approvals granted earlier in the year. Ethereum ETFs accumulated $982.5 million over the trailing 30-day period, including $17.1 million on Sept. 28. Solana-focused funds drew $278.2 million during the month, while XRP products captured $127.05 million. These figures underscore a maturation of the U.S. spot ETF landscape beyond Bitcoin, though BTC-denominated funds still command roughly three-quarters of total monthly volume across all approved digital asset tickers.

Bitcoin traded near $84,045 heading into October, with 24-hour volume hovering around $1.5 billion.