BlackRock, the world’s largest asset manager, has crossed a line that once seemed unthinkable: through its iShares Bitcoin Trust (IBIT), it now controls around 3.8% of the total Bitcoin supply.

As Bloomberg’s Senior ETF analyst Eric Balchunas quipped, an equity ETF would need to amass “$2.2 trillion in assets” to achieve a similar footprint in its underlying market.

By contrast, SPY, the granddaddy of equity ETFs with three decades of history, only holds about 1.1% of most stocks. IBIT, still a toddler by ETF standards, has managed in a year what traditional funds could not in a generation.

The scale is staggering. IBIT’s net assets now stand at $87.7 billion, helping push BlackRock’s total crypto portfolio above $102 billion by the end of Q3, according to Finbold research in Q3 Cryptocurrency Market Report.

In the three months to September, the portfolio swelled by $22.46 billion, including a $10.9 billion gain in Bitcoin holdings and a sharp $11.46 billion increase in Ethereum exposure, the latter climbing more than 260%.

The trajectory since January tells the fuller story. After dipping in Q1 when BlackRock’s portfolio briefly contracted by almost $5 billion the firm has added more than $35 billion in crypto assets year-to-date, with the strongest inflows coming in the first half and steady expansion in Q3. What started as a cautious foothold has turned into a structural position.

U.S. spot Bitcoin ETFs pull in $57 billion in inflows since launch

IBIT is not operating in isolation. Collectively, U.S. spot Bitcoin ETFs have pulled in $57 billion in inflows since launch, including $21.5 billion this year alone. Yet IBIT has emerged as the dominant force, capturing the lion’s share of those allocations and cementing BlackRock as one of Bitcoin’s largest single holders.

For Bitcoin itself, the irony is hard to miss. The asset once cast as Wall Street’s antidote is now being hoarded by its most powerful institution.