Key Takeaways
- DeFi (decentralized finance) recreates financial services such as trading, lending and borrowing using smart contracts instead of banks.
- You use DeFi with a self-custody wallet, and you keep control of your funds until you deposit them into a protocol.
- Core building blocks include decentralized exchanges, lending markets, stablecoins and liquid staking.
- Risks include smart contract bugs, hacks, liquidations, scams and the lack of any customer support or deposit insurance.
Decentralized finance, or DeFi, is one of crypto's most important and most misunderstood ideas. It promises banking-style services that anyone with an internet connection can use, run by code rather than companies. This guide explains what DeFi is, how it works, what you can do with it and the risks to understand before you try it.
What is DeFi?
DeFi is a collection of financial applications built on public blockchains, mostly Ethereum and its layer 2 networks, plus chains such as Solana. Instead of a bank deciding who can borrow or trade, the rules are written into smart contracts: programs that run automatically on the blockchain and treat every user the same way.
Because these apps are open and on-chain, anyone can use them without an account, credit check or minimum balance, and anyone can inspect how they work.
How DeFi differs from traditional finance
| Traditional finance | DeFi | |
|---|---|---|
| Who runs it | Banks and brokers | Smart contracts |
| Access | Accounts, ID checks, business hours | A wallet and an internet connection, 24/7 |
| Custody | Institution holds your money | You hold your keys |
| Transparency | Private ledgers | Public, auditable transactions |
| Protection | Deposit insurance, customer support | Usually none |
What can you do with DeFi?
Trade on decentralized exchanges (DEXs)
DEXs like Uniswap let you swap one token for another directly from your wallet. Instead of an order book, most use liquidity pools: pots of two tokens supplied by users, with prices set by a formula. You never hand your funds to an exchange operator.
Lend and borrow
Lending protocols such as Aave let you deposit crypto to earn interest or borrow against your deposits. Loans are over-collateralized: to borrow $1,000 of stablecoins you might need to deposit $1,500 or more of ETH. If your collateral's value falls too far, the protocol automatically sells it in a liquidation.
Use stablecoins
Dollar-pegged stablecoins are the cash of DeFi, used for trading, lending and payments.
Earn yield
Users can earn fees by supplying liquidity to DEXs, interest from lending, or rewards from liquid staking. Yields change constantly, and very high advertised returns usually signal very high risk.
Other uses
DeFi also includes derivatives, insurance-style coverage pools, tokenized real-world assets such as treasury funds, and cross-chain bridges that move tokens between blockchains.
How to get started with DeFi
- Set up a self-custody wallet such as MetaMask or a Solana wallet, and back up your seed phrase offline. For larger amounts, connect a hardware wallet.
- Buy crypto on an exchange and withdraw it to your wallet. Keep some of the network's native coin, such as ETH, to pay transaction fees.
- Choose a low-cost network. Layer 2 networks such as Arbitrum, Optimism and Base offer much lower fees than Ethereum's main network.
- Use well-known protocols with long track records and public audits. Bookmark their official URLs.
- Start small with an amount you're comfortable losing while you learn.
The risks of DeFi
- Smart contract bugs: a single coding error can let attackers drain a protocol. Audits reduce but don't remove this risk.
- Hacks and bridge exploits: cross-chain bridges in particular have been the target of some of crypto's largest thefts.
- Liquidations: sharp price drops can wipe out borrowers' collateral.
- Impermanent loss: liquidity providers can end up with less value than if they had simply held their tokens.
- Scams and rug pulls: anonymous teams can launch tokens or protocols and disappear with deposits. Learn the red flags.
- Malicious approvals: signing a transaction on a fake site can give an attacker permission to move your tokens. Regularly review and revoke token approvals you no longer need.
- No safety net: there's no customer support or deposit insurance, and transactions can't be reversed.
- Regulation and tax: rules are still evolving, and many DeFi actions, such as swaps, can be taxable events.
Frequently asked questions
Is DeFi safe?
DeFi is riskier than using a regulated bank or exchange. Using established, audited protocols, starting small and protecting your wallet reduce the risk but can't eliminate it.
Do I need ID to use DeFi?
Most DeFi protocols don't require identity checks because you interact directly with smart contracts. However, the exchanges you use to buy crypto, and some front-end websites, may require them.
Can I lose money in DeFi?
Yes, through falling prices, liquidations, hacks, scams or mistakes. Funds lost in DeFi are rarely recovered.
What is TVL in DeFi?
Total value locked (TVL) is the value of all assets deposited in a protocol or across DeFi. It's a rough measure of size and popularity, not of safety.
Is DeFi only on Ethereum?
No. Ethereum and its layer 2 networks host the largest share of DeFi, but there are major ecosystems on Solana, BNB Chain and other blockchains.
New to the terminology? Check our crypto glossary.
This guide is for educational purposes only and is not financial advice.
This content is for educational purposes only and is not financial advice. Cryptocurrency investments are volatile and risky. Some links may be affiliate links — see our disclosure.