Why Aggregators Will Dominate the Bundler Landscape

Bundlers are a commodity. The core function of constructing and submitting UserOperations is a low-margin, execution-only service. This invites a race to the bottom where the only sustainable advantage is superior transaction sourcing.

Aggregators control the supply. Just as 1inch and CoW Protocol dominate liquidity routing, specialized intent-based aggregators like Biconomy and Stackup will dominate user flow. They abstract wallet complexity and own the customer relationship.

The data proves vertical integration. Ethereum's MEV supply chain shows that entities controlling order flow (e.g., Flashbots) capture the majority of value. Account abstraction's bundler market will follow the same consolidation pattern.

Solo builders are structurally disadvantaged. They lack the consistent, high-volume transaction flow required to win a meaningful share of block auctions on chains like Ethereum. This creates a winner-take-most dynamic where liquidity and order flow consolidate.

Aggregators centralize order flow. Protocols like Flashbots' SUAVE and EigenLayer's EigenDA are not just builders; they are intent aggregation networks. They pool orders from many sources, achieving the scale needed to outbid isolated actors.

The endpoint is the battleground. User acquisition shifts from chain-level to RPC-level. The entity controlling the user's transaction endpoint (e.g., a wallet's default RPC) dictates builder selection. This is why Coinbase's Base and Consensys' Infura are existential threats to generic RPC providers.

Evidence: On Ethereum post-PBS, the top three builders consistently control over 80% of block production. This concentration mirrors the CEX/DEX aggregation pattern seen with 1inch and CowSwap, where liquidity follows the best execution.

Bundler fragmentation is inefficient. Every wallet, dApp, and chain operates a separate bundler, creating redundant infrastructure and suboptimal user pricing. This mirrors the pre-aggregator DEX landscape where liquidity was siloed across Uniswap, SushiSwap, and Curve.

Aggregators capture value. Bundler aggregators like Alchemy's Rundler and Biconomy's infrastructure abstract complexity. They route user operations to the most efficient execution path, similar to how 1inch or CoW Protocol aggregates liquidity, extracting fees from the routing layer.

The endpoint is the moat. Aggregators that own the primary RPC endpoint for developers, like Alchemy, control the entry point. This creates a natural bundling monopoly, akin to how Infura dominates Ethereum RPC access despite numerous node providers.

Evidence: The top five ERC-4337 bundlers process over 80% of all UserOperations. This concentration, despite hundreds of deployed bundlers, demonstrates the inevitable aggregation dynamic.

Aggregation is inevitable. A single bundler cannot consistently offer the best execution across all blockchains and intents. The winner-takes-most dynamics seen in DEXs (1inch, UniswapX) and bridges (Across, Socket) prove that users and wallets route to the aggregator offering the optimal route, not a single source.

Bundlers become a commodity. The technical act of constructing and submitting a bundle is a low-margin operation. The real value accrues to the intent-solving layer that finds the best path across competing bundlers, private mempools, and solvers, just as CowSwap aggregates solvers.

The endpoint is the moat. For DEXs, it's the swap interface. For bundlers, it's the RPC endpoint (like Blink or Privy). Wallets and dApps will integrate the aggregator endpoint that guarantees the best user experience and lowest cost, abstracting away the fragmented backend.

Evidence: 1inch's dominance. Despite thousands of DEX pools, 1inch commands ~50% of DEX aggregator volume by consistently routing to the best price. The same liquidity network effects will solidify around a leading bundler aggregator, making it the default entry point for user intents.

Bundling is a commodity service. The core function of ordering and submitting transactions to an L1 is simple. The real value accrues to the entity controlling the user relationship and the order flow, not the execution layer. This is why PGA auctions and MEV capture define the market.

Aggregators own the demand side. Protocols like UniswapX and CowSwap already aggregate user intents and route them to the most efficient solver. They will extend this model to become the primary source of bundled transactions, dictating terms to a fragmented pool of execution bundlers.

Decentralization adds latency and cost. A decentralized network of permissionless bundlers requires consensus or complex auction mechanisms for every block. This creates proposer-builder separation (PBS) overhead that centralized aggregators bypass, offering users faster, cheaper finality.

Evidence: Ethereum's PBS model shows specialization wins. Block building is centralized with Flashbots and BloXroute, while proposers (validators) remain decentralized. The same dynamic will play out in the rollup bundler market, with aggregators as the dominant builders.

Aggregators centralize execution liquidity. Individual bundlers face capital constraints for staking and paymasters. Aggregators like EigenLayer AVS operators and Rhinestone pool this capital, creating a more robust and reliable network for builders.

They abstract away fragmentation. Developers must choose between Pimlico's paymaster, Alto's account abstraction, and Gelato's automation. A meta-aggregator standardizes these services, turning a complex integration into a single API call.

The economic model shifts to aggregation fees. The MEV supply chain (searchers > builders > proposers) is the template. Aggregators will capture value by routing user operations to the most efficient bundler, not by running one.

Evidence: Ethereum's PBS (Proposer-Builder Separation) proves this model. Just as builders outcompete solo validators, bundler aggregators will outcompete standalone bundlers on reliability and cost.