BIS Flags Blockchain Sequencers and Middleware for FMI-Style Oversight

The Bank for International Settlements has published a Bulletin examining why blockchain activity has spread across dozens of separate networks rather than consolidating, and identifying a regulatory consequence that operators should note: certain cross-chain infrastructure is, in the BIS view, approaching systemic importance.

The paper draws an explicit parallel with Swift. Interoperability protocols that pass verified messages between blockchains, shared sequencers that determine transaction ordering across multiple networks, and data availability layers that publish transaction records for public verification are all identified as analogues to messaging infrastructure that, as it scaled, eventually attracted formal central bank oversight. The BIS states these components may warrant governance arrangements, resilience standards, and supervisory attention comparable to those applied to financial market infrastructures (FMIs).

The BIS frames network fragmentation as structurally inevitable rather than a failure of coordination. Blockchain design involves fundamental trade-offs: higher hardware requirements for validators enable faster and cheaper transactions but reduce participation, while Bitcoin and Ethereum prioritised broad validator access and accepted congestion and higher fees as a result. Because no single set of choices is optimal for every use case, dozens of networks with distinct user bases, assets, and liquidity pools persist in parallel.

The practical signal here is directional rather than immediate. The BIS is not announcing a supervisory framework; it is signalling that the operators running shared sequencers and interoperability middleware should expect regulatory scrutiny to follow the same arc as Swift’s, and that the absence of formal oversight today does not indicate its absence tomorrow.