BlackRock has sparked controversy within the Bitcoin community after releasing a three-minute video about Bitcoin. The video explains Bitcoin's core features, including its fixed supply of 21 million coins — a feature considered sacred by its supporters. However, a small but crucial disclaimer in the video drew attention:
> “There is no guarantee that Bitcoin’s 21 million supply cap will not be changed.”
This statement alarmed many Bitcoiners, with some speculating that BlackRock might be hinting at future attempts to alter Bitcoin’s supply cap. One community member questioned whether BlackRock was "coming up with a way to implement a hard fork" to increase the cap, while others called the message "spooky."
BlackRock's Influence on Bitcoin
BlackRock currently manages over 524,000 Bitcoin (valued at $53 billion) through its Bitcoin exchange-traded fund (ETF). Given its significant influence, concerns have been raised that BlackRock may try to change Bitcoin’s fundamental rules, echoing past struggles over control of the protocol.
The Blocksize War (2015-2017)
This controversy brings up memories of the Blocksize War from 2015-2017, when exchanges and miners clashed over the size of Bitcoin’s transaction blocks. The battle was seen as a power struggle over control of Bitcoin’s protocol. Ultimately, the "small blockers" — those advocating for smaller block sizes — prevailed.
Why the Supply Cap Matters
Bitcoin’s 21 million supply cap is seen as a cornerstone of its value proposition. Supporters argue that it prevents inflation and protects Bitcoin from the kind of debasement seen in traditional fiat currencies. If this limit were to be removed, many believe it would undermine Bitcoin’s credibility and value.
The Debate Over Miner Payments
Despite strong support for the 21 million cap, some argue that Bitcoin’s security model may need to evolve. Currently, miners are paid through block rewards (newly issued Bitcoin) and transaction fees. However, block rewards are designed to halve every four years, leading to concerns that future transaction fees alone may not be enough to sustain miners.
Developer Nikita Zhavoronkov has argued that the 1 MB block size limit needs to be raised to generate more transaction fees, but others, like crypto custodian Casa’s CTO Jameson Lopp, view the future of Bitcoin's security budget as a philosophical — not technical — issue. Lopp believes the best solution is to drive wider Bitcoin adoption to ensure adequate fees for miners.
The Bigger Picture
While BlackRock’s disclaimer may have been a legal safeguard, it has rekindled old fears about outside influence over Bitcoin’s rules. The Bitcoin community remains staunchly protective of its supply cap, viewing it as essential to Bitcoin's role as "sound money" and a hedge against inflation. Whether BlackRock's comment was a warning or a mere formality, it has undoubtedly reignited a critical debate about Bitcoin’s future.