A yield aggregator vault is a DeFi smart contract that automatically manages capital across multiple protocols to maximise returns – harvesting rewards, compounding gains, rebalancing, and optimising strategies on behalf of depositors. Pioneered by Yearn Finance (launched 2020 by Andre Cronje), yield vaults abstract DeFi complexity: a user deposits a single token (USDC, ETH) and the vault strategy automatically deploys it across lending markets, liquidity pools, and farming opportunities. Vaults continuously harvest governance token rewards (COMP, CRV, AAVE) and sell them for more of the base asset, compounding APY. Gas costs for harvesting are socialised across all depositors – making vaults cost-effective even for small deposits. Vault strategies are written by strategists and audited before deployment. Risks include reliance on the security of every protocol in the strategy path – a hack in any component can drain the vault. Performance fees (typically 2% management plus 20% performance) are charged by the protocol. Convex Finance and Yearn are the largest aggregators by TVL, managing billions across hundreds of automated strategies.
Example: Example: A user deposits 10,000 USDC into a Yearn USDC vault. The strategy deploys funds into Curve 3pool (earning trading fees plus CRV), stakes on Convex (boosting CRV rewards), auto-harvests weekly, sells CRV for USDC, and compounds. Net APY: 8% vs 4% if held in Aave directly. The vault automates 10 transactions per week at no extra cost to the depositor.
Learn more: Yearn Finance
