Briefing
The foundational problem of Miner Extractable Value (MEV) in Automated Market Makers (AMMs) stems from the block producer’s ability to control transaction ordering, leading to arbitrage opportunities and an off-chain centralization risk. This research proposes a new AMM mechanism that processes all transactions within a block as a single, atomic batch, ensuring that a constant potential function is maintained across the entire execution. This architectural shift formally guarantees arbitrage resilience at the application layer, fundamentally securing the financial primitive against predatory value extraction regardless of the underlying consensus protocol’s sequencing fairness, thus stabilizing the core infrastructure of decentralized finance.
Context
The established theory of constant function market makers (CFMMs), such as the constant product model, is inherently path-dependent → the final state of the liquidity pool and the resulting price depend on the sequential order in which trades are executed within a block. This path-dependence is the precise theoretical limitation that creates MEV, as it allows a block producer to strategically insert transactions → front-running and back-running → to capture the price difference, which is a risk-free profit. The prevailing academic challenge was to design a mechanism that is logically sequencing-agnostic within a block without resorting to complex, often incomplete, consensus-layer fairness solutions.
Analysis
The paper’s core mechanism is a batch-clearing process that replaces sequential execution with simultaneous, unified settlement. Instead of updating the pool state after each transaction, the mechanism collects all user trades submitted in a block and calculates a single, market-clearing price and allocation for the entire batch. The new primitive is a mechanism that enforces the invariant → the pool’s state before the batch and its state after the batch must both satisfy the chosen constant potential function (e.g. $x cdot y = k$).
By enforcing this invariant across the aggregate change, the mechanism eliminates the transient, exploitable price deviations between sequential trades that arbitragers rely upon. This fundamentally differs from previous AMMs by removing the block producer’s ability to profit from transaction ordering, as all transactions are effectively treated as one single, large trade.
Parameters
- Arbitrage Resilience → Miner cannot gain risk-free profit. This guarantee holds even when the block producer has unilateral control over block contents and transaction sequencing.
- Incentive Compatibility → Users are incentivized to report true demand. This stronger guarantee is achieved when the underlying consensus provides a weak form of sequencing fairness.
- Constant Potential Function → The core mathematical invariant (e.g. $x cdot y = k$) must be maintained by the pool state after processing the entire transaction batch.
Outlook
This mechanism design opens a new research avenue focused on application-layer MEV mitigation, strategically shifting the burden away from complex, often incomplete, consensus-layer fairness protocols. The theoretical breakthrough enables the construction of provably fair financial primitives. Future work will focus on generalizing this batch-clearing model to more complex decentralized financial instruments, such as lending protocols and options markets, creating a new class of strategy-proof, fair decentralized financial infrastructure within the next three to five years.
Verdict
The introduction of a batch-clearing invariant for Automated Market Makers represents a critical, formal advancement in mechanism design, proving that application-layer architecture can mathematically eliminate the systemic risk of Miner Extractable Value.
