US spot Bitcoin ETF balances are negative without BlackRock

Over the past year, Bitcoin’s exchange-traded fund (ETF) boom has been celebrated as proof that Wall Street has finally embraced crypto. Yet the numbers reveal something far more fragile.

On Oct. 28, Vetle Lunde, head of research at K33 Research, noted that US-traded Bitcoin ETFs have attracted about $26.9 billion in inflows year-to-date.

However, that headline figure hides a stark imbalance that BlackRock’s iShares Bitcoin Trust (IBIT) alone accounts for roughly $28.1 billion of those flows.

In other words, Bitcoin ETFs would be in net outflows this year without IBIT. The product’s relentless accumulation has single-handedly offset redemptions across competitors, keeping aggregate inflows positive and sustaining Bitcoin’s narrative of institutional adoption.

A market held by one fund

Since launching in early 2024, IBIT has dominated every major performance metric in the ETF ecosystem.

According to SoSo Value data, it has seen about $65.3 billion in lifetime inflows, compared to $21.3 billion across all other Bitcoin funds combined.

Meanwhile, Grayscale’s GBTC has suffered roughly $24.6 billion in redemptions, confirming that without IBIT, the aggregate picture would be deeply negative.

This effectively means that BlackRock’s IBIT scale stands in a league of its own.

The fund drew $37 billion in its debut year and has added another $28 billion so far in 2025, pushing its total assets under management past $90 billion, which is well ahead of any competitor.

According to Coinperps data, Bitcoin ETFs collectively hold about 1.3 million BTC, and IBIT accounts for over 60% of that entire stash.

Why BlackRock’s IBIT was able to dominate

A significant part of IBIT’s growth can be linked to the fact that BlackRock has used its $12.5 trillion AUM, retail brokerage channels, and institutional relationships to channel demand into a single flagship product.

The asset manager’s entry into the emerging industry instantly conferred legitimacy on a sector still reeling from the broader crisis of trust.

Eric Balchunas, Bloomberg ETF Analyst, said:

Apart from that, the fund’s recent success can also be linked to how Bitcoin has transformed BlackRock’s investor base.

Last year, the firm revealed that three out of four IBIT investors were entirely new to BlackRock’s iShare product suite.

This shows that IBIT has become not just a crypto ETF but also a client-acquisition engine for the world’s largest asset manager.

Indeed, the asset manager’s custom creation mechanisms have become increasingly popular among large Bitcoin holders, or “whales,” who were once wary of traditional financial institutions. These mechanisms allow investors to transfer their Bitcoin directly to the ETF in exchange for new shares, bypassing the need to sell on the open market.

So far, the firm has reportedly processed over $3 billion in such in-kind transfers, reflecting the strong confidence in its custodial design and long-term exposure model.

This strong dominance has created a halo effect that has proven very profitable for BlackRock.

Barely more than a year old, IBIT already ranks as BlackRock’s top ten revenue generators, surpassing long-standing funds like the iShares Russell 1000 Growth ETF.

What happens when the flows slow?

IBIT’s overarching dominance of the Bitcoin ETF space begs the question of what will happen when its numbers eventually slow down.

If IBIT’s inflows taper, the immediate impact would be felt across market liquidity and price stability. At its current size, even a modest reduction in buying could remove a significant source of consistent demand. That demand has acted as a quasi-monetary inflow, offsetting miner sell pressure and exchange outflows.

A slowdown would therefore widen spreads on US spot exchanges, reduce arbitrage opportunities for market makers, and weaken the feedback loop that has kept Bitcoin’s price anchored above key support levels. In essence, the ETF bid has become Bitcoin’s floor, and IBIT is most of that bid.

The knock-on effects would also ripple through institutional sentiment.

If month-over-month flows turn negative, family offices and RIA desks benchmarking performance to IBIT could rebalance away from Bitcoin ETFs entirely. That withdrawal would lower the “liquidity premium” currently embedded in Bitcoin’s price.

Finally, a sustained stagnation in IBIT inflows could shift capital toward Ethereum and newly launched altcoins ETFs, eroding Bitcoin’s dominance ratio.

However, Lunde pointed out that BlackRock’s absence from these product suites could limit their overall net flows.