Aave is the largest decentralized lending protocol by total value locked. Users deposit crypto as collateral to earn yield, or borrow against it at variable interest rates — without a bank, broker, or credit check. Founded in 2017 under the name ETHLend, Aave has operated continuously through multiple market cycles and now runs across more than a dozen blockchains.
Why Aave exists
Traditional lending runs through banks: credit checks, paperwork, fixed business hours, and approval that can be denied for reasons that have nothing to do with the collateral on offer. For crypto holders specifically, the gap was even more limiting — the only way to access cash against your holdings was to sell them, triggering a taxable event and giving up any further upside.
Aave's promise is to remove the gatekeeping. Markets are permissionless: anyone with an internet connection and assets to deposit can lend or borrow, with no identity check and no approval process. Rates are set algorithmically and visible on-chain to everyone, rather than negotiated behind closed doors. Deposits that would otherwise sit idle in a wallet earn passive yield automatically. Borrowers can unlock liquidity against their holdings without selling them, keeping their original position intact.
The same openness also makes Aave a building block for the rest of DeFi. Its markets are composable — other protocols and applications can plug into Aave's liquidity rather than building their own, which is part of why it has become a default piece of infrastructure rather than just one app among many.
How the protocol works
Aave is a pool-based money market with two sides: lenders who deposit assets to earn yield, and borrowers who draw against their own collateral. Five mechanics hold the whole system together.
Lending. Users deposit a supported asset — ETH, a stablecoin, wrapped Bitcoin, and many others — into a shared liquidity pool. In return, they receive an interest-bearing token representing their deposit, which accrues yield automatically in real time as borrowers pay interest. No manual claiming or compounding required.
Borrowing. Users post an asset as collateral and draw a loan against it in a different asset of their choosing. Because there's no credit check, every loan must be overcollateralised — the collateral's value always exceeds the amount borrowed. The required buffer depends on the volatility and liquidity of the assets involved: more volatile collateral demands a larger cushion.
The health factor. Every borrowing position carries a live ratio between the value of its collateral and the value of its debt. If that ratio drops below a set threshold — because the collateral lost value or the debt grew — the position becomes eligible for liquidation: part of the collateral is sold off to repay the debt and restore the pool to safety.
Interest rates. Rates on both sides adjust algorithmically based on utilisation — the share of a pool's deposits currently lent out. Higher utilisation pushes rates up, attracting new deposits and discouraging further borrowing; lower utilisation does the reverse. This keeps each market roughly balanced without manual intervention.
Market structure. Markets are organised by asset, and increasingly by isolated risk parameters: newer or more volatile assets can be listed with stricter limits so a problem in one market doesn't automatically threaten the rest of the protocol.
How Aave makes money
Aave's revenue comes from four mechanisms, all tied directly to lending and borrowing activity rather than speculative trading volume.
Borrow interest (reserve factor). When borrowers pay interest, a set percentage — the reserve factor — goes to the Aave treasury instead of to lenders. This is the dominant revenue stream, and it scales directly with borrowing demand: more borrowing means more interest paid, means more revenue captured.
Liquidation fees. When a borrower's collateral value falls below the required threshold, their position is liquidated to protect lenders. Aave charges a penalty on this process, a portion of which flows to the treasury.
Flash loan fees. Flash loans are uncollateralised loans that must be borrowed and repaid within a single transaction. They're used mainly by developers for arbitrage and collateral swaps, and each one carries a small fixed fee.
GHO borrow interest. GHO is Aave's own native stablecoin. Users mint it by locking collateral in Aave markets, and the interest on outstanding GHO flows to the treasury — an increasingly important lever as stablecoin adoption grows across the protocol.
Reading Aave's metrics
TVL. For a lending protocol, TVL is more directly tied to revenue than in most DeFi categories — every dollar locked represents collateral backing real borrowing demand. Rising TVL expands the base from which interest income is generated; a sustained decline compresses it. Aave has historically held the leading position among DeFi lending protocols, with its closest peers typically carrying meaningfully smaller TVL.
Revenue trend. Because the reserve factor is a percentage of interest paid, revenue moves with both TVL and the broader interest-rate environment in crypto markets. The absolute revenue figure matters less than its trend relative to TVL over a rolling 30-day window — a rising ratio means the protocol is capturing more economic value per dollar locked, independent of whether TVL itself is growing or shrinking.
FDV/TVL. Aave's token supply is nearly fully circulating, so FDV and market cap sit close to identical — there's little dilution risk to factor in, unlike protocols with large unvested allocations still to unlock. That makes FDV/TVL a comparatively clean valuation signal here: a low ratio suggests the market prices the protocol below the capital it manages, though whether that reflects undervaluation or appropriately priced-in risk depends on the broader picture — revenue trajectory, competitive position, and the risk factors below.
Risk factors
Smart contract risk. Aave runs a complex, multi-chain, multi-version codebase. A vulnerability in any single market or version can create losses for users. The Safety Module, funded by staked AAVE, exists to cover bad debt — but it's a backstop, not a guarantee.
Third-party collateral risk. Aave doesn't control what assets users post as collateral. If an accepted asset loses value faster than liquidations can process — through a price crash, bridge exploit, or stablecoin depeg — bad debt can accumulate on Aave's markets even when Aave's own code functions exactly as designed.
Governance and contributor risk. Decentralised governance means there's no management team with fiduciary accountability. Shifts in contributor incentives or governance disputes can slow execution or create coordination friction — a structural trade-off for the censorship-resistance that decentralisation provides.
Regulatory risk. As one of the highest-profile DeFi protocols, Aave operates across jurisdictions with regulatory frameworks that vary widely and continue to evolve. Action in any major market could affect user access or the token's legal treatment elsewhere.
How to monitor Aave without daily research
The three numbers worth tracking regularly are TVL direction, the revenue-to-TVL trend, and the FDV/TVL ratio. TokenSignal tracks all three automatically — connect Aave to your watchlist for a daily digest of TVL and revenue changes, plus alerts when meaningful shifts occur. Free for up to 5 assets.
Related: What is TVL in DeFi?