How DeFi Interest Rates Work: Supply, Demand, and Protocol Mechanics
DeFi interest rates are set algorithmically, not by central banks. This guide explains how utilization-based rate models work, why rates spike, and how to find consistent yield.
In traditional finance, interest rates are set by central banks and loan committees. In DeFi, rates are set by algorithms responding to real-time supply and demand. Understanding these mechanics helps you predict when rates will be high and when to enter or exit lending positions.
Utilization-Based Rate Models
- Utilization = Borrowed Amount / Total Supplied Amount
- Low utilization (20%): low borrow rates (2–4%) to encourage more borrowing
- High utilization (80%): rates rise sharply to incentivize more supply and deter borrowing
- Kink point: most protocols have a kink at 80–90% utilization where rates spike dramatically
Why Rates Spike Temporarily
- Market events: sudden demand for USDC to buy a dip pushes utilization to 95%+
- Liquidations: cascade liquidations increase borrow demand as positions need to repay
- Airdrop farming: mass borrowing to farm a new protocol token creates utilization spikes
- Rates normalize within hours as new supply enters to chase the temporarily high APY
Finding Consistent Rate Opportunities
On-chain rate monitoring tools (Morpho Rate, DeFi Yield) track historical lending rates across protocols. Consistent lending yield (not spiky) is found in: USDC on Aave Arbitrum (steady 6–8%), stablecoin LPs on Curve (steady 8–12% from fees), and RWA products tied to external rates (Ondo USDY). The most stable yields come from real economic sources, not utilization spikes.