Why Shared Sequencing Will Spark the Next Wave of DeFi Innovation

Monolithic sequencers capture 100% of MEV and transaction ordering rights, creating a centralized point of failure and rent extraction. This stifles innovation and user trust.

• Extracted Value: Billions in MEV kept by sequencer operators.
• Censorship Risk: Single entity can front-run or block transactions.
• Innovation Lock-in: No competition for better execution or privacy.

Shared sequencers like Espresso, Astria, and Radius create a competitive auction for block space. Builders bid for the right to order transactions, returning value to users and apps.

• Proposer-Builder Separation (PBS): Decouples block building from proposing.
• MEV Redistribution: Auctions can fund public goods or user rebates.
• Atomic Composability: Enables cross-rollup transactions within a single block.

Shared sequencing is the required infrastructure for intent-based architectures like UniswapX and CowSwap. Solvers compete to fulfill user intents across rollups, with the sequencer providing the atomic settlement layer.

• Expressiveness: Users submit "what" not "how".
• Efficiency: Solvers find optimal cross-domain routes.
• Guaranteess: Atomic execution prevents partial fills across chains.

Projects like dYdX Chain and Fuel use validator-based sequencing. Shared sequencing networks generalize this into a Proof-of-Stake layer dedicated to ordering, with slashing for liveness faults.

• Economic Security: Stake secures sequencing, not just consensus.
• Fast Finality: Pre-confirmations with crypto-economic backing.
• Permissionless Participation: Any entity can join the sequencer set.

Rollups no longer need to bootstrap validator sets. They outsource to specialized providers, paying for liveness and performance. This turns a capex burden into a variable opex.

• Instant Launch: New rollups deploy in hours, not months.
• Economies of Scale: Shared security and infrastructure costs.
• Revenue Share: Rollups can earn a cut of sequencing fees/MEV.

With a shared sequencing layer, applications like MarginFi and Aave can treat multiple rollups as a single state machine. This enables cross-rollup flash loans and unified liquidity pools without bridging delays.

• Unified Liquidity: Aggregates fragmented TVL across the stack.
• Zero-Latency Arbitrage: Eliminates cross-domain MEV opportunities.
• Native Composability: Smart contracts interact seamlessly across rollups.

A shared sequencer must choose two: decentralization, liveness, or correctness. Most opt for liveness, creating a single point of failure. A malicious or faulty sequencer can censor or reorder transactions, breaking atomic composability across rollups.\n- Security Risk: A single sequencer failure halts dozens of rollups.\n- Trust Assumption: Users must trust the sequencer's output is correct.

Centralizing block production for multiple chains consolidates MEV extraction into a single, powerful entity. This creates a super-searcher with a global view, enabling cross-rollup arbitrage and frontrunning at an unprecedented scale.\n- Economic Capture: A sequencer cartel can extract >30% of cross-domain MEV.\n- User Cost: 'Fair ordering' promises are untested at scale against economic incentives.

Shared sequencers like Astria, Espresso, and Radius create competing, isolated clusters of rollups. This fragments liquidity and composability, replicating the very problem they aim to solve. A rollup on Astria cannot atomically compose with one on Espresso without a trusted bridge.\n- New Silos: Replaces L1 silos with sequencer silos.\n- Complexity: Forces developers to choose an ecosystem before building.

Sequencer revenue is a tax on rollup transactions. To be viable, a shared sequencer needs >$100M+ in annualized fees from its rollups. This creates perverse incentives to prioritize high-volume, MEV-rich chains over niche app-chains, centralizing the rollup landscape around a few winners.\n- Fee Pressure: Rollups face a new revenue share cost center.\n- Centralizing Force: Economics favor a monolithic 'sequencer stack'.

Today, executing a strategy across multiple rollups (e.g., arbitrage between Uniswap on Arbitrum and Aave on Optimism) is non-atomic and high-risk. You face frontrunning and execution slippage.

• Solution: A shared sequencer provides a single, atomic ordering layer.
• Result: Enables cross-rollup MEV capture and composable arbitrage as a native primitive, similar to a cross-chain flash loan.

Rollups inherit L1 finality times, creating ~12-second latency for cross-domain communication. This kills high-frequency trading and real-time leveraged positions across chains.

• Solution: Shared sequencers like Espresso or Astria offer fast, firm pre-confirmations.
• Result: Enables sub-second cross-rollup interactions, opening DeFi to HFT strategies and real-time derivatives previously confined to CEXs.

DeFi's core innovation—composability—is broken across rollups. A vault on Base cannot natively use a liquidity position on zkSync. This creates capital inefficiency and stifles innovation.

• Solution: A shared sequencing layer acts as a synchronization point, allowing rollups to read each other's state pre-confirmation.
• Result: Unlocks native cross-rollup composability, enabling new primitives like cross-domain money markets and unified liquidity pools without bridges.

Today, each rollup's sequencer is a centralized, profit-extracting black box. It's a regulatory target and a censorship risk, undermining crypto's core value proposition.

• Solution: Decentralized shared sequencer networks (e.g., Espresso, Astria, Radius) introduce permissionless proposer sets and cryptoeconomic security.
• Result: Censorship resistance returns to L2, sequencer profits are democratized, and the stack becomes credibly neutral infrastructure.