For educational purposes only; not investment advice. Investing may result in loss.
Direct answer
A liquidation bonus is the extra collateral value a lending protocol makes available when someone repays an eligible borrower’s debt. It compensates liquidators for gas, slippage, price movement, failed transactions, and competition. From the borrower’s perspective, the same amount is a liquidation penalty because more collateral leaves the account than the debt value repaid.
The bonus is not a universal rate. It can differ by protocol, deployment, collateral asset, market mode, and governance configuration. Aave documents that a position becomes liquidatable when its health factor falls below 1; the liquidator repays debt and receives equivalent collateral value plus a bonus. The transaction can be permissionless without being guaranteed profitable.
Do not confuse the quoted bonus with net profit. A protocol may retain part of the bonus, and the liquidator still pays execution and financing costs. Some systems also use a different liquidation architecture. Compound III, for example, first uses protocol reserves to absorb an underwater account and later offers the protocol-held collateral for discounted purchase. The caller of absorb does not simply receive the borrower’s collateral in the same transaction.
How it works
In a simplified direct-seizure design, let D be the debt value repaid, b the liquidation-bonus rate, and C the collateral value removed from the borrower at the protocol’s oracle prices:
C = D * (1 + b)
The gross bonus value is D * b. If f is the share of that bonus directed to the protocol, the simplified split is:
liquidator collateral value = D + D * b * (1 - f)
protocol collateral value = D * b * f
These are teaching equations, not transaction quotes. Token decimals, rounding, oracle units, close-factor limits, available collateral, and protocol-specific rules affect the actual amounts. Aave V3’s liquidation code, for example, calculates base collateral from oracle prices, applies the configured liquidation bonus, and can deduct a configured liquidation protocol fee from the bonus portion for the treasury.
The incentive has to balance two losses. If it is too small, expected proceeds may not cover gas, slippage, adverse price movement, or failed bids, so risky debt may remain unliquidated. If it is too large, borrowers lose more collateral and a sudden oracle move can consume the solvency buffer faster. Governance therefore usually configures liquidation parameters alongside collateral factors, liquidation thresholds, close factors, and oracle design.
Protocol names are not interchangeable. Compound v2 calls its multiplier the liquidation incentive and may direct a seize share to reserves. Compound III separates absorb from buyCollateral: reserves pay down the account first, the protocol takes the collateral, and buyers may later purchase that inventory at a discount when reserve conditions permit. Always inspect the rules and live configuration of the specific market.
Worked example
Assume a direct-seizure market allows a liquidator to repay 1,000 USDC with b = 5%. At the protocol’s oracle prices, the borrower loses collateral worth 1,050 USDC. If f = 10% of the bonus goes to the protocol, the 50 USDC gross bonus is split into 45 USDC of liquidator value and 5 USDC of protocol value.
The liquidator therefore receives collateral worth 1,045 USDC for repaying 1,000 USDC. If gas and priority fees cost 12 USDC and swapping the collateral creates 8 USDC of slippage and fees, the simplified net result is 25 USDC:
net result = 45 - 12 - 8 = 25
This example assumes the transaction succeeds at the expected oracle and execution prices. It excludes failed bids, financing costs, price movement before sale, token transfer restrictions, and taxes. A nominal 5% bonus is therefore neither a guaranteed 5% return nor necessarily the amount the liquidator keeps.
Risks
- Oracle and price-gap risk: Seized collateral is calculated from the protocol’s accepted price, but the realizable market price can move before it is sold.
- Execution and MEV risk: Competing liquidators may outbid or front-run a transaction. Reverted attempts still consume gas, while private order flow and auctions can redirect part of the surplus.
- Liquidity risk: A quoted bonus can be smaller than slippage when the collateral is thinly traded, capped, bridged, paused, or difficult to transfer.
- Parameter risk: Governance or authorized risk managers can change bonus rates, protocol fees, thresholds, or close-factor rules. Interface values may lag the current on-chain configuration.
- Bad-debt risk: A bonus encourages action but cannot create collateral. A price gap, stale oracle, congestion, or insufficient collateral can still leave the protocol with a deficit.
- Borrower loss: Liquidation is irreversible once finalized and can remove more collateral than the repaid debt. A partial liquidation can also leave the borrower exposed to another liquidation.
Common misconceptions
Myth 1: The liquidation bonus is free protocol yield
The bonus is paid from the borrower’s collateral. It is compensation for executing a risky, competitive transaction, not interest created by the protocol without a payer.
Myth 2: A quoted 5% bonus guarantees 5% profit
Protocol fees, gas, priority fees, slippage, hedging, financing, failed attempts, and price movement all reduce the result. Profit must be measured against the collateral’s realizable sale value, not only the oracle value.
Myth 3: A larger bonus always makes a lending market safer
A larger incentive can improve execution, but it also increases borrower loss and the collateral consumed per unit of debt repaid. Safety depends on oracle quality, liquidity, thresholds, close factors, transaction capacity, and parameter calibration together.
Myth 4: Every liquidator receives collateral directly
That describes some protocols, including the basic Aave-style flow, but not every design. Compound III can have the protocol absorb the position and sell collateral separately, so the actor triggering liquidation and the eventual collateral buyer need not be the same address.
Related topics
Sources
- Health Factor & Liquidations - Aave (accessed: 2026-08-21)
- Aave V3 LiquidationLogic.sol - Aave (accessed: 2026-08-21)
- Compound v2 Docs: Comptroller - Compound Finance (accessed: 2026-08-21)
- Compound III Docs: Liquidation - Compound Finance (accessed: 2026-08-21)