Batch Auction
After the pool price is rebalanced by the Arbitrage Auction, Angstrom batches all user trades at a uniform clearing price each block. This neutralizes sandwich attacks and provides consistent execution.
Key Steps
- Collect Orders: Any user or market maker limit orders are gathered into one batch.
- Form a Single Clearing Price: Orders meet a supply/demand curve that includes on-chain AMM liquidity and off-chain limit orders, culminating in a single intersection price. See Order-Matching to learn more about how the matching engine works.
- Execute: All orders in the batch execute at this single uniform price.
Why Batch Auctions?
- No Sandwiching: If all trades within a block settle at the same price, front-running or reordering for short-term gain is pointless.
- Unified Liquidity Aggregation: Unlike batch auctions like CowSwap that select a single solver’s solution per batch, Angstrom treats all orders and AMM liquidity as part of a unified orderbook. Multiple market makers and solvers can contribute simultaneously, integrating their orders into the supply/demand curve alongside the rebalanced pool liquidity—driving deeper liquidity, stronger price competition, and superior execution for users.
- Reduced Slippage: Large orders benefit from pooled liquidity and off-chain market maker liquidity.
- Fair Gas Dynamics: Because the trade execution is order agnostic, there is no reason to pay higher gas for priority.
Combined Benefit
When combined with the Arbitrage Auction, batch auctions ensure that:
- LPs receive full compensation for stale quotes (LVR).
- Swappers get a stable, uniform price per block without the risk of getting front-run or sandwiched.