Why Shared Sequencing Hubs Will Challenge Dominant L2s

Every major L2 runs its own sequencer, a $1B+ annualized revenue business locked in silos. This creates massive redundancy and opportunity cost.

• Economic Drag: Capital is tied up in redundant hardware and staking, not user incentives.
• Fragmented Liquidity: MEV is trapped per-chain, reducing extractable value for builders and users.
• Wasted R&D: Each team reinvents the wheel on PBS, pre-confirmations, and fast finality.

Native cross-rollup UX is broken. Users and apps pay a hidden tax in latency, complexity, and security risk with bridges like LayerZero and Across.

• Latency Silos: Moving assets between Arbitrum and Optimism takes ~10 minutes, killing composability.
• Security Fragmentation: Each new bridge adds another trusted oracle or multisig, increasing systemic risk.
• Developer Hell: Integrating multiple L2s requires custom messaging layers and liquidity pools.

A neutral, auction-based sequencing layer that commoditizes block production. This is the L2 equivalent of AWS vs. on-prem servers.

• Atomic Composability: Enables cross-rollup transactions within a single block, unlocking new app paradigms.
• MEV Redistribution: Centralizes MEV auction, returning value to rollups and users instead of a single sequencer.
• Instant Finality: Provides sub-second pre-confirmations by leveraging a shared network of attesters.

The Problem: L2s are locked into their own sequencers, creating centralization risks and missed MEV opportunities.\nThe Solution: A configurable, shared sequencer network that L2s and rollups can plug into.\n- HotShot consensus enables ~1-2 second finality for connected chains.\n- Timeboost feature allows users to pay for priority ordering, creating a transparent MEV market.

The Problem: Building a performant, decentralized sequencer is a massive engineering burden for new rollups.\nThe Solution: A shared sequencer that provides instant, censorship-resistant block production as a service.\n- Enables sovereign rollups to outsource sequencing while retaining settlement and DA.\n- No forking required—rollups can migrate from a centralized sequencer without a hard fork.

The Problem: Isolated L2s fragment liquidity and prevent complex, cross-chain DeFi strategies.\nThe Solution: Shared sequencers enable atomic execution across multiple rollups in a single block.\n- A single transaction can atomically swap assets on a zkSync rollup and borrow on an Arbitrum rollup.\n- This creates a unified liquidity layer that directly challenges the walled-garden value proposition of dominant L2s.

The Problem: MEV extraction by sequencers undermines user experience and creates toxic arbitrage.\nThe Solution: A shared sequencer that uses practical verifiable delay encryption (PVDE) to create a private mempool.\n- Transactions are encrypted until they are included in a block, neutralizing frontrunning.\n- Provides credible neutrality and fair ordering, making it the preferred utility layer for user-centric apps.

The Problem: Major L2s derive value and control from bundling execution, sequencing, and settlement.\nThe Solution: Shared sequencers unbundle the stack, reducing L2s to high-security settlement layers.\n- Optimism and Arbitrum become akin to Ethereum L1—secure but not monopolistic.\n- Innovation and user experience shift to the shared sequencing utility layer, commoditizing the L2 execution client.

The Problem: New shared sequencers lack the billions in staked economic security that Ethereum provides.\nThe Solution: Leverage EigenLayer restaking and NEAR's data availability to bootstrap security and reduce costs.\n- Avail and EigenDA provide high-throughput, low-cost DA for sequencer batches.\n- Restaked ETH can secure the sequencing layer's consensus, creating a trust-minimized bridge to Ethereum's economic security.

Dominant L2s like Arbitrum and Optimism bundle sequencing, proving, and settlement to capture ~90% of MEV and enforce vendor-locked liquidity. This creates a fragmented, expensive user experience where cross-chain is a necessity, not a feature.\n- Captured Value: Sequencer profits are not shared with the ecosystem.\n- Fragmented Liquidity: TVL is siloed, increasing capital inefficiency.\n- Protocol Lock-in: Building on an L2 means adopting its entire, often suboptimal, stack.

Decouple transaction ordering from execution. A neutral, decentralized sequencer network (like Espresso Systems, Astria, Radius) provides fast pre-confirmations and orders blocks for multiple rollups. This enables atomic composability across chains and democratizes MEV.\n- Cross-Rollup Atomicity: Enables native, trust-minimized composability between sovereign chains.\n- MEV Redistribution: Sequencer profits can be shared via MEV-Boost-like auctions.\n- Execution Agnosticism: Rollups can switch execution clients without rebuilding their sequencer set.

With sequencing commoditized, the competitive moat for L2s shrinks to execution efficiency and settlement guarantees. This forces a reversion to first principles: who has the fastest VM (Ethereum, Solana VM, Move VM?) and the most secure data availability layer (EigenDA, Celestia, Avail?).\n- VM Wars Resume: Performance benchmarks become the primary differentiator.\n- DA as a Commodity: High-throughput, low-cost DA becomes a baseline expectation.\n- Specialized Rollups: Niche chains for gaming, DeFi, or privacy can thrive without operational overhead.

The logical conclusion is for the underlying L1 validator set (e.g., Ethereum via ePBS, Cosmos via Interchain Security) to become the universal sequencer. This provides the strongest economic security and finality, turning rollups into pure execution layers. Projects like Near DA and EigenLayer restaking are early signals.\n- Maximum Security: Inherits the full economic security of the base layer.\n- Canonical Finality: Eliminates re-org risks from competing sequencer sets.\n- Ultimate Neutrality: No single L2 operator controls the transaction pipeline.