BlackRock’s bitcoin exchange-traded funds (ETFs) have emerged as the investment giant’s most lucrative product line, a surprising revelation highlighted by Cristiano Castro, the director of business development at BlackRock Brazil, during the Blockchain Conference in São Paulo. This development is particularly striking considering that BlackRock oversees more than 1,400 ETFs worldwide and is recognized as the largest asset manager globally, with over $13.4 trillion in assets under management.
Castro described the success of the bitcoin ETFs, which include the U.S.-based IBIT and Brazil’s IBIT39, as “a big surprise,” noting that allocations in these funds have neared the staggering figure of $100 billion. “When we launched, we were optimistic,” he remarked, “but we didn’t expect this scale.”
The U.S.-listed spot bitcoin ETF, IBIT, launched in January 2024, made headlines by becoming the fastest fund in history to amass $70 billion in assets, achieving this milestone in just 341 days. This impressive growth trajectory has persisted despite the inherent volatility associated with bitcoin’s price fluctuations. As per data from SoSoValue, the ETF currently boasts $70.7 billion in net assets.
In its inaugural year, IBIT recorded net inflows exceeding $52 billion, significantly outpacing all other ETFs introduced in the last decade. Additionally, it generated an estimated $245 million in annual fees by October 2025. The surge in interest can be attributed to BlackRock’s extensive global distribution network and increased institutional enthusiasm following U.S. regulatory approval for spot bitcoin ETFs. Notably, IBIT now holds more than 3% of bitcoin’s total supply and has been accompanied by a range of other bitcoin-linked products launched by BlackRock, including exchange-traded products (ETPs) in international markets.
Addressing concerns surrounding recent outflows from bitcoin funds, Castro indicated that such fluctuations are typical behavior for retail investors during price declines. “ETFs are a very liquid and powerful tool. They’re meant for people to manage flows,” he explained. Moreover, BlackRock itself has shown confidence in its bitcoin ETF; its Strategic Income Opportunities Portfolio has recently increased its stake in IBIT by 14%.
While inquiries were made regarding the recent developments, BlackRock had not responded at the time of writing.
