Aave
Oracle de Taux de Prêt
Context
This figure appears at the start of Section 4.1 'Lending Rate Oracle' within the 'Stable Rate Theory' chapter, which explains how the stable borrow rate is anchored to real-world market lending rates. The oracle is the first component introduced in the stable rate system. It shows how rate data from multiple lending platforms is aggregated into the average market lending rate (Mr).
What This Figure Shows
The Lending Rate Oracle figure illustrates how the Aave protocol collects interest rate data from both centralized and decentralized lending platforms and computes a volume-weighted average market lending rate (Mr). The formula is Mr = (sum of each platform's lending rate multiplied by its borrowing volume) divided by the total borrowing volume across all platforms. This rate is updated daily, initially by Aave itself, and is fed into the stable rate formula described in Section 4.2. Mr acts as the floor or base for the stable borrow rate — Aave's stable rate starts at Mr and then increases with utilization using the same two-slope model as the variable rate. By anchoring to external market rates, Aave ensures its stable rate is competitive and economically rational rather than arbitrary.
Significance
The Lending Rate Oracle is what makes Aave's stable rate genuinely reflective of market conditions rather than a purely internal calculation. By incorporating rates from other lending platforms — both on-chain and off-chain — the protocol connects DeFi rates to the broader credit market, reducing the risk of persistent arbitrage between Aave's stable rate and other venues. The oracle's role in anchoring the stable rate also limits manipulation: a borrower who tries to depress rates by flooding the pool with liquidity would still face a floor set by external market rates.
