Why Bundlers Will Kill Generalized Frontrunning

Bundlers centralize execution power. They aggregate user transactions into single blockspace bids, shifting the competitive arena from public mempools to private order flow. This removes the raw transaction data that public searchers and MEV bots rely on for frontrunning.

The kill mechanism is economic. Projects like Flashbots SUAVE and EigenLayer create markets for block space where bundlers bid for inclusion. This formalizes value capture, making parasitic frontrunning unprofitable compared to cooperative bundling.

Evidence from existing rollups. Arbitrum and Optimism already use sequencers that function as mandatory bundlers, processing over 1M transactions daily. Their private mempools have rendered generalized frontrunning on these L2s economically negligible.

Bundlers monetize order flow, not latency. In a traditional mempool, searchers profit from public transaction data via MEV extraction. A bundler's business model is fee-based revenue from processing UserOperations, creating a direct incentive to secure private order flow from wallets and dApps to guarantee execution.

Private mempools become the default. Projects like EigenLayer and Flashbots SUAVE are building infrastructure for confidential order flow. Wallets (e.g., Safe) and dApps will auction their users' transaction bundles directly to a network of trusted bundlers, bypassing the public Ethereum mempool entirely.

Generalized frontrunning requires public data. The classic sandwich attack is impossible without visibility into pending transactions. By moving intent settlement off-chain into these private auction channels, the raw material for predatory MEV disappears. Searchers must provide explicit value via backrunning or arbitrage.

Evidence: The CEX model proves it. Centralized exchanges like Coinbase and Binance have never suffered generalized frontrunning because order flow is internalized. Account Abstraction's bundler-searcher separation recreates this dynamic in a decentralized, permissionless network.

Permissionless entry kills cartels. Any entity can run a bundler, creating an open market for block space. This is the same dynamic that prevents L1 miners from colluding on fees, but with lower capital requirements.

User sovereignty fragments power. Unlike MEV searchers who hunt for value, bundlers serve user-submitted intents. The order flow belongs to the user, who can route it to any bundler via a public mempool or solver network like UniswapX or CowSwap.

Economic incentives enforce honesty. A cartel raising prices creates a profit opportunity for a new bundler to undercut it. This is a Nash equilibrium where the dominant strategy is competitive pricing, not collusion.

Evidence: The existing PBS (Proposer-Builder Separation) model on Ethereum proves this. Despite builder concentration, new entrants like Titan and Rsync consistently capture market share by offering better execution, preventing stable cartel formation.