DeFi, short for decentralized finance, is a set of financial services — trading, lending, borrowing, saving — built on public blockchains and run by smart contracts instead of banks or brokers. Anyone with a crypto wallet can use DeFi apps directly, 24/7, without opening an account or asking permission.
Key takeaways
- DeFi apps are smart contracts, mostly on Ethereum, its Layer 2s and other smart-contract chains.
- Core building blocks: stablecoins, decentralized exchanges (DEXs), lending markets and staking.
- You keep custody of your funds — but you also carry all the responsibility.
- Yields come with real risks: smart contract bugs, liquidations, depegs and scams.
How DeFi works
In traditional finance, a bank holds your money, matches lenders with borrowers and takes a cut. In DeFi, those rules are written into open-source smart contracts. You connect a self-custody wallet, approve a transaction, and the contract does the rest — instantly and transparently, with every action visible on the blockchain.
DeFi apps are often called «money legos» because they plug into each other: a token earned in one protocol can be used as collateral in another.
The main types of DeFi apps
Stablecoins
Tokens designed to hold a steady value, usually $1. They’re the base currency of DeFi. Learn how they work in what are stablecoins?
Decentralized exchanges (DEXs)
DEXs let you swap tokens directly from your wallet. Most use automated market makers (AMMs): instead of an order book, trades happen against liquidity pools — pots of two tokens supplied by users, who earn a share of trading fees in return.
Lending and borrowing
Lending protocols let you deposit assets to earn interest, or borrow against your crypto. Loans are over-collateralized: to borrow $500 you might need to deposit $800 or more of ETH. If your collateral’s value falls too far, it’s automatically sold (liquidated) to repay the loan.
Liquid staking
Stake ETH or other proof-of-stake assets and receive a token representing your staked position, which you can still use elsewhere. See crypto staking explained.
Derivatives, yield aggregators and more
Perpetual futures, options, automated yield strategies and tokenized real-world assets like treasury bills — all built from the same building blocks.
DeFi vs traditional finance
| Traditional finance | DeFi | |
|---|---|---|
| Access | Account approval, business hours | Anyone with a wallet, 24/7 |
| Custody | Institution holds your funds | You hold your funds |
| Transparency | Internal books | Public, on-chain |
| Settlement | Days | Seconds to minutes |
| Consumer protection | Deposit insurance, dispute processes | Generally none |
| Main risks | Institutional failure, fees | Code bugs, user error, volatility |
Where does DeFi yield come from?
Always ask: who is paying me, and why? Sustainable DeFi yield usually comes from real activity:
- Borrowers paying interest on loans.
- Traders paying swap fees to liquidity providers.
- Network rewards from staking.
Very high yields are often paid in a protocol’s own newly printed tokens, which can lose value quickly — or they are simply unsustainable. If you can’t identify the source of the yield, you may be the source.
The risks of DeFi
- Smart contract risk: bugs and exploits have caused large losses. Audits help but are not guarantees.
- Liquidation risk: volatile collateral can be sold off at a loss.
- Impermanent loss: liquidity providers can end up worse off than simply holding when prices move.
- Stablecoin depegs: «stable» assets have broken their peg before.
- Oracle manipulation: protocols relying on price feeds can be attacked.
- Governance and admin keys: some «decentralized» protocols can be changed by a small group.
- Phishing and malicious approvals: fake front-ends can drain wallets — see common crypto scams.
How to start with DeFi safely
- Learn the basics of wallets and seed phrase security.
- Use a dedicated hot wallet with a small amount you can afford to lose.
- Start on a low-fee Layer 2 network to keep costs down.
- Stick to long-running, widely used protocols, and bookmark their official URLs.
- Read every transaction before signing, and revoke old approvals regularly.
Confused by DeFi jargon like TVL, slippage or impermanent loss? Our crypto glossary explains them in one sentence each.
Frequently asked questions
Is DeFi safe?
DeFi carries significant risks, from code exploits to user mistakes. Established protocols have long track records, but no protocol is risk-free. Only use funds you can afford to lose.
Do I need to verify my identity to use DeFi?
Most DeFi smart contracts don’t require identity verification, though some front-end websites restrict access in certain countries. Your on-chain activity is public and may still be subject to tax and legal obligations.
What blockchain is best for DeFi?
Ethereum and its Layer 2 networks host the largest share of DeFi activity, with other ecosystems like Solana also popular. Fees, available apps and security differ between them.
