MEV Landscape and Extraction Dynamics

Maximal Extractable Value (MEV) on Starknet presents a distinct risk profile that diverges significantly from Ethereum's well-studied PBS and MEV-Boost landscape. The protocol's current single-sequencer architecture concentrates transaction ordering power, creating a trusted operator model where the sequencer has unilateral ability to front-run, back-run, and sandwich user transactions. Unlike Ethereum's competitive builder market, Starknet lacks an in-protocol mechanism for proposer-builder separation or an encrypted mempool, meaning all pending transactions in the public mempool are visible and exploitable by the sequencer operator until decentralized sequencing and privacy-preserving transaction submission are implemented.

Starknet's native account abstraction introduces MEV surfaces absent from EOAs on Ethereum. The __validate__ and __execute__ separation in Cairo smart accounts creates multi-phase transaction execution where the sequencer can observe validation outcomes before committing to execution ordering. Paymaster architectures add further complexity: third-party paymasters that sponsor gas can be griefed through MEV extraction that maximizes their token expenditure, while bundler-like entities that batch user operations face similar extractable value dynamics to ERC-4337 bundlers on Ethereum. DeFi protocols on Starknet must model these account abstraction-specific MEV vectors, including cross-call atomicity risks where a sequencer can reorder user operations within a single account's multicall.

The SHARP shared prover infrastructure adds a cross-chain MEV dimension. Because Starknet shares proof aggregation with other StarkWare-based chains, the timing of proof submission and state finalization can create cross-domain MEV opportunities where state transitions on one chain are observed before another's proofs are settled. For builders, wallet teams, and DeFi protocols operating on Starknet, understanding these extraction dynamics is essential for designing MEV-resistant applications, configuring slippage protections, and preparing for the transition to decentralized sequencing. Chainscore Labs provides MEV risk assessments for Starknet deployments, including paymaster griefing analysis, sequencer trust assumption modeling, and mitigation strategy reviews for teams building on Cairo.

Starknet's MEV landscape is fundamentally shaped by its centralized sequencer model, which eliminates the priority gas auction (PGA) and proposer-builder separation (PBS) dynamics that dominate Ethereum's MEV supply chain. The single sequencer has full discretion over transaction ordering within a block, making it the sole arbiter of extraction opportunities. This architecture transforms MEV from an open, competitive market into a permissioned, operator-controlled function. The sequencer can theoretically engage in front-running, back-running, and sandwich attacks without the constraints of a public mempool, as transactions are submitted directly to the sequencer and are not broadcast to a peer-to-peer network before inclusion.

Starknet's native account abstraction introduces additional MEV surfaces that do not exist on Ethereum. Smart accounts can implement custom validation logic, and paymasters can sponsor transaction fees under arbitrary conditions. A sequencer observing the calldata of a user operation can simulate its validation phase to identify profitable opportunities—such as a paymaster that refunds a large fee or an account that uses a manipulable oracle during validation. Bundlers, which aggregate user operations for submission, represent another extraction point. A bundler can reorder operations within a bundle or selectively censor operations that would compete with its own extraction strategies. The __validate__ and __execute__ separation in Starknet accounts creates a two-phase transaction lifecycle where value can be extracted in either phase if the sequencer or bundler can predict state changes.

The fee market model adds a further dimension. Starknet separates L2 execution fees from L1 data availability fees, and the sequencer sets both. This dual fee structure creates an information asymmetry where the sequencer can price transactions based on its private knowledge of pending state changes. A sequencer aware of a large oracle update or liquidation opportunity in the pending transaction set can adjust fee parameters to capture value. For DeFi protocols, traders, and wallet teams operating on Starknet, understanding these surfaces is critical. Chainscore Labs can provide MEV risk assessments that map extraction vectors specific to a protocol's account architecture, paymaster dependencies, and oracle usage, and can review mitigation strategies such as encrypted mempool designs or fair-ordering commitments as Starknet's sequencer decentralization roadmap progresses.