BlackRock’s bitcoin exchange-traded funds (ETFs) have become the firm’s most profitable product line, according to Cristiano Castro, director of business development at BlackRock Brazil.
The number is remarkable considering that the firm manages over 1,400 ETFs globally and is the world’s largest asset manager with more than $13.4 trillion in assets under management.
Speaking at the Blockchain Conference in São Paulo to local media, Castro called the development “a big surprise” and said allocations in the firm’s bitcoin ETFs, including the US-based IBIT and Brazil’s IBIT39, had come close to $100 billion.
“When we launched, we were optimistic,” Castro said, “but we didn’t expect this scale.”
The firm’s US-listed spot bitcoin ETF IBIT, launched in January 2024, became the fastest in history to reach $70 billion in assets, doing so in 341 days. That momentum has continued despite recent volatility in bitcoin’s price, with the ETF currently sitting at $70.7 billion in net assets, according to SoSoValue data.
Net inflows exceeded $52 billion in the first year, which was far higher than any other ETF launched in the last decade. IBIT also generated an estimated $245 million in annual fees by October 2025.
IBIT’s rapid growth has been fueled by BlackRock’s global distribution network and a wave of institutional interest following US regulatory approval of spot bitcoin ETFs. It now has over 3% of bitcoin’s total supply, and it was followed by various BTC-linked products from BlackRock, including ETPs overseas.
Addressing recent outflows from bitcoin funds, Castro said such a move is expected given how retail investors tend to react to price declines. “ETFs are a very fluid and powerful tool. They’re meant for people to manage flows,” he said.
BlackRock itself has bet on its bitcoin ETF. Its Strategic Income Opportunities recently raised its stake in IBIT by 14%.
CoinDesk has reached out to BlackRock, but did not hear back at the time of writing.
