DeFi (Decentralized Finance)
In simple terms
DeFi is like banking, but instead of going to a bank to save money or get a loan, you use computer programs on the internet that do the same thing automatically. There's no company or person in the middle taking a cut.
Definition
Financial services built on blockchain technology without traditional intermediaries like banks.
In depth
DeFi comprises financial protocols deployed on blockchain networks that enable peer-to-peer transactions, lending, borrowing, and asset swapping through smart contracts rather than centralized intermediaries. Users interact directly with liquidity pools and automated market makers (AMMs) secured by consensus mechanisms, while transactions are validated by distributed networks of nodes. DeFi services rely on oracles to bring external price data on-chain and use cryptographic verification to ensure transaction integrity without requiring KYC or traditional credit checks.
How does DeFi (Decentralized Finance) work?
DeFi replaces the intermediary in a financial service with a smart contract, code deployed to a public blockchain that anyone can call. A user connects a self-custody wallet to an application, approves the contract to move a specific token, then submits a transaction. A lending protocol holds deposits in a shared pool and lets borrowers draw against collateral worth more than the loan; if that collateral's value falls past a threshold, anyone can trigger a liquidation. An exchange protocol prices swaps from the ratio of two assets held in a pool. Every step settles on-chain, so no support desk exists to reverse a mistake.
An example
Someone deposits $1,000 of collateral into a lending protocol requiring 150% collateralization, which allows borrowing up to about $666 of a stablecoin. Using illustrative figures, if the collateral's value drops to $900, the position falls below the required ratio and can be liquidated automatically with a penalty deducted. Borrowers watch that buffer closely. Interest rates in these pools float with how much of the pool is borrowed rather than being fixed at the start.
Figures are illustrative only.
What beginners get wrong
- Granting unlimited token approvals to a contract and never revoking them, which leaves the wallet exposed if that contract is later exploited.
- Borrowing near the maximum leaves almost no buffer, so an ordinary price move can trigger liquidation and the penalty that comes with it.
- An audit is not a safety guarantee; audited contracts have still been exploited, and audits cover a snapshot of the code rather than every risk.
- Chasing an advertised yield without asking where it comes from, when unusually high rates usually reflect unusually high risk of total loss.
Related terms
Part of
What is DeFi, and how does decentralized finance work? — the subject page for defi, with all 18 of its definitions in one place.
Educational only — not financial advice.