Michael Saylor warns about OP_RETURN: over 80 bytes reignite the clash

Michael Saylor returns to emphasize the theme of ossification of Bitcoin and raises the level of alert: changing the protocol is not a detail, but a potential threat to the entire ecosystem. His stance is clear: fewer modifications, more stability. His observations have been reported by industry publications and protocol analysts and enter the broader debate that starts from the Bitcoin whitepaper.

According to data collected by node operators and on-chain monitoring reports, the use of additional payloads beyond 80 bytes has shown, in laboratory tests and permissive configurations, a measurable increase in mempool load and peer-to-peer traffic. For example, 50 additional bytes per transaction on 100,000 transactions generate about 5 MB of extra data; on a daily and monthly scale, this can translate into hundreds of megabytes or several gigabytes additional depending on the usage rate. Industry analysts note that such increases, while not impacting consensus, can raise the operational costs of nodes and the barrier to entry for new participants.

The debate has resurfaced around proposals related to the use of OP_RETURN. At the center is the idea of increasing the amount of data carried in “data-carrying” transactions, with implications for nodes, decentralization, and operational costs.

Saylor, Executive Chairman of Strategy – a company that holds one of the largest Bitcoin treasuries, advocates for a conservative stance. The message is clear and divisive: the “lack of a feature” can itself be a feature. In this context, the priority is to preserve the consistency of the protocol over time, avoiding changes that create difficult precedents to manage.

What Happened: The Crux of the OP_RETURN Debate

The discussion, recently emerging in technical circles (developers’ mailing list and GitHub thread), revolves around the data threshold allowed via OP_RETURN in node forwarding policies. It should be noted that these are not consensus rules, but default settings that impact transaction propagation.

• Technical context: the current policy limit for OP_RETURN is 80 bytes (Bitcoin Developer Guide and GitHub Bitcoin Core).
• Proposal under review: explore an increase in the transportable data (currently, there is no publicly consolidated definitive value).
• Sensitive point: more data in the blocks can increase storage burdens, bandwidth, and synchronization times.

The stakes are not just technical. A change that appears to be “of second or third order” can have ripple effects on governance, incentives, and perception of security. That said, the balance between flexibility and stability remains delicate and also depends on the adoption of policy by the operators.

Why Saylor Talks About Threat: The Logic of Ossification

According to Saylor, every change to the protocol should be scrutinized as a potential risk. The fear is the “sliding door effect”: small adjustments today could create greater pressures tomorrow.

There are two key ideas: on one hand, more changes mean more surfaces for errors; on the other, a coordinated attack could consist of financing endless attempts at “improvements” until forcing a misstep. In other words: “value” and trust also arise from predictability. Indeed, continuity in the rules is seen as a bulwark against drifts that, in the long run, could undermine the neutrality of the system.

The statements highlight a position that, although criticized in certain circles, emphasizes the importance of keeping the base protocol of Bitcoin unchanged.

OP_RETURN in brief: what it is and its technical effects

OP_RETURN is an operation that allows attaching a small amount of data to a transaction, making the output provably unspendable. It does not change the consensus rules, but falls under the nodes’ policy rules, which decide what to forward or accept by default.

Current policy limit: 80 bytes. A potential increase would not affect consensus, but could have operational impacts. Among the expected effects: more data in mempool and blocks, greater size of the history to store, and a possible increase in fees to compete for the extra data space. Yet, those advocating for the expansion believe that the fee market can balance opportunistic behaviors.

Synthetic Technical Impact

• Storage: faster growth of the blockchain and index files.
• Bandwidth: more traffic between nodes and longer synchronization times for new participants.
• Abuses: risk of spam or inscriptions that exploit the data-carrier at the expense of pure financial transactions.
• Policy vs consensus: the change affects the relay policy and does not obligate the entire network, but it can create operational divergences.

Other voices: objections and counter-arguments

Part of the community recalls that the settings on OP_RETURN are policy choices, therefore adjustable and reversible. According to this interpretation, the fee market filters abuses and incentivizes efficient use of space.

On the other hand, supporters of ossification fear the precedent: normalizing the addition of non-financial data could shift Bitcoin from an essential monetary ledger to a “generic transport” of payloads, with repercussions on decentralization in the long term. In this context, the focus is on keeping the cost of operating a node low.

What it means for investors

For those holding BTC, the message is pragmatic: more stability in the rules, less regulatory and technical uncertainty. The absence of new features can preserve security and the predictability of fees, key elements for long-term trust.

The flip side is a slower pace of innovation at the base level, with a growing push towards second layer solutions and off-chain tools. However, technological layering is already part of Bitcoin’s architecture and allows for experimentation without touching the core of the protocol.

Status of the Proposal and Next Steps

Currently, at the time of publication (September 19, 2025), there is no change in consensus nor any merge in Bitcoin Core. Discussions continue in mailing lists and public repositories. Any policy changes will require a broad convergence among maintainers, node operators, and infrastructures. That said, the process remains gradual and marked by open reviews, precisely to measure the impact before making operational decisions.

Quick FAQ

What is meant by “ossification”? It is the choice to minimize changes to the base protocol to preserve stability and security. In other words, to minimize risk surfaces over time.

Does OP_RETURN concern consensus? No: it is a policy rule of the nodes (relay/acceptance) and not a consensus rule. This implies that the settings can vary without fragmenting the fundamental rules.

Is there an official number for the proposed increase? Currently, there are no established values: some ideas are circulating, but no definitive parameter has been publicly adopted. The phase is exploratory and the discussion remains open.

How is Bitcoin protected from unnecessary risks? Through public reviews, thorough testing, minimal and measurable interventions, and the adoption of bug fixes and compatibility, while structural changes are considered only in the presence of a clear necessity supported by robust evidence. In fact, the guiding principle is to avoid non-essential changes.