In-depth essays · #26 / 50 · On-Chain Finance (DeFi), Stablecoins & RWA
How On-Chain Lending Works Without Credit Scores: Inside Aave, Morpho, and Automated Liquidations
Overcollateralization, utilization rate interest curves, and health-factor liquidations explained
Borrowing from a traditional bank requires identity checks, income verification, and days of underwriting. Inside Ethereum City’s lending shops—such as Aave and Morpho—a pseudonymous address can borrow millions of dollars in stablecoins in a single 12-second block. Here is the mechanism that keeps those protocols solvent through market crashes.
1. Why Borrow Against More Collateral Than the Loan Value?
DeFi lending relies on overcollateralization: depositing $1,000 of ETH might let you borrow up to $750–$800 of USDC. Users do this to unlock working cash without selling long-term ETH holdings (and triggering a taxable sale), or to express directional leverage.
2. Algorithmic Interest Rates Driven by Pool Utilization
No committee sets interest rates in DeFi. Instead, a mathematical curve adjusts supply and borrow APRs every block based on the pool’s utilization rate. When liquidity is abundant, rates stay low; if utilization crosses the optimal ‘kink’ (often 80–90%), rates spike sharply to attract fresh deposits and prompt repayments.
3. Health Factors and Permissionless Liquidations
Each loan has a Health Factor tracking collateral value relative to the liquidation threshold. The moment market prices push a borrower’s Health Factor below 1.0, any external liquidator bot can repay part of the debt in exchange for seizing the borrower’s collateral at a small discount (the liquidation bonus), extinguishing bad debt before it hits depositors.
4. From Monolithic Pools (Aave) to Modular Isolated Markets (Morpho)
Alongside Aave’s multi-asset liquidity pools, Morpho popularized isolated, immutable lending markets paired with curated vaults—letting depositors choose exact collateral risks.
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This essay is an explainer written to help you read the city; it is not investment advice. Facts on this page are as of 2026-10 and may change. If you spot a mistake, please tell us through the contact page.