Bitcoin ETF inflows of $2.4B tighten supply as exchanges lose 35,800 BTC in a single week

Roughly 35,800 BTC vanished from exchange wallets last week. Not into thin air, but into ETF vaults and cold storage, the kind of places where coins go to sit quietly for a very long time.

US spot Bitcoin ETFs pulled in approximately $2.4 billion in net inflows for the week ending September 25, making it the strongest weekly haul since early October 2025. That capital didn’t just pad fund balances. It physically removed Bitcoin from the liquid supply pool.

Who’s buying and how much

BlackRock’s IBIT led the charge with roughly $1.2 billion in weekly inflows, maintaining its position as the dominant vehicle for institutional Bitcoin exposure. Fidelity’s FBTC followed at about $702 million, with ARK 21Shares’ ARKB contributing approximately $295 million.

Since launching in January 2024, cumulative net inflows across all US spot Bitcoin ETFs have now surpassed $57 billion. Total assets under management sit at roughly $108 billion.

Year-to-date ETF flows had actually turned negative earlier this year, bottoming out at approximately negative $5.8 billion in mid-July. The reversal since then has been sharp enough to push 2026 flows back into positive territory, now sitting at around $934 million in the black.

Exchange reserves are draining fast

On the other side of the equation, centralized exchanges saw net outflows of about 31,782 BTC, worth roughly $2.52 billion at current prices. Binance alone accounted for nearly 19,500 BTC in withdrawals, more than half the total.

On-chain data suggests holders are increasingly transitioning Bitcoin into long-term storage as market sentiment improves.

From capitulation to conviction

Mid-July’s trough of negative $5.8 billion in cumulative 2026 flows represented a genuine crisis of confidence for the ETF ecosystem. The recovery since then has been decisive enough to quiet most of those concerns.

The $108 billion in total ETF assets under management puts Bitcoin funds in rarefied territory among commodity-linked products. For comparison, it took gold ETFs years after their 2004 debut to reach similar scale. Bitcoin’s ETF complex accomplished it in under three years.

What the supply squeeze means going forward

Bitcoin’s supply is capped at 21 million coins, with roughly 19.7 million already mined. When ETFs absorb tens of thousands of BTC weekly while exchanges simultaneously bleed inventory, the available float for active trading contracts.

BlackRock’s dominance at roughly half of weekly inflows suggests IBIT is becoming the default allocation vehicle, potentially at the expense of smaller competitors who may struggle to maintain relevance as the market matures.

Disclosure: This article was edited by Vivian Nguyen. For more information on how we create and review content, see our Editorial Policy.