DeFi (Decentralized Finance) is finance running on smart contracts instead of banks. You lend, borrow, trade and earn yield from your own wallet, 24/7, without paperwork. The hero below shows what your money can earn in five different places. Move the slider to see real numbers.
New protocol yield farmingToken rewards on launch protocols
25% APY
High
+$2,500/yr
Section 01 · Quick answer
What it is, how it works, where it bites
What it is
Banking-style services running on smart contracts instead of banks. Lend, borrow, trade, earn yield - directly from your wallet, 24/7. Total value locked: ~80-100B USD as of 2026.
How it works
Connect a self-custody wallet (Metamask, Phantom) to a protocol website. Sign transactions to deposit, borrow, trade. Smart contract enforces the rules - no human approves anything.
Where it bites
Smart contract bugs, oracle failures, impermanent loss, outright scams. 3+ billion USD lost to DeFi hacks in 2022 alone. Stick to top-10 protocols with audits.
Section 02 · DeFi vs banks
DeFi vs traditional finance
Same financial actions, very different mechanics. The DeFi side trades trust-in-institutions for trust-in-code. Both have failure modes; they are just different ones.
Action
TradFi (bank)
DeFi
Save USD
~4% APY, FDIC insured up to 250K USD, weekday business hours
5-8% APY on USDC in Aave, no insurance, 24/7 withdraw
Borrow 1,000 USD
Credit check, 7-30 days, 8% APR, can be denied
Instant, no credit check, 4-6% APR, must overcollateralize with crypto
Swap USD to EUR
~25 USD wire fee, 1-3 business days
~1 USD fee, 1 minute, any token pair
Risk if it fails
FDIC pays up to 250K, takes weeks
You lose what you deposited, no recovery
Section 03 · Six categories
The six DeFi categories
Almost everything in DeFi falls into one of these. Knowing the six covers 95% of what you will see.
01Lending
Aave, Compound, Morpho
Deposit crypto, earn interest. Borrow against your crypto without selling. 5-8% APY on USDC is typical.
02DEX (decentralized exchange)
Uniswap, Jupiter, PancakeSwap
Swap any token for any token, no account, no KYC. Provide liquidity to a pool to earn trading fees.
03Liquid staking
Lido, Rocket Pool, Jito
Stake ETH or SOL to secure the network, get a tradeable receipt token (stETH, jitoSOL). 3-7% APY.
04Stablecoins
DAI, LUSD, FRAX
Crypto-backed dollars. Used as the unit of account across all DeFi. See stablecoins guide.
05Derivatives
dYdX, GMX, Hyperliquid
Perpetual futures and options on-chain. Same mechanics as crypto futures but no exchange custody.
06Yield aggregators
Yearn, Pendle, Convex
Smart contracts that auto-route your deposit to whichever protocol pays the highest yield right now. Saves manual rebalancing.
Section 04 · How to start
How to actually start using DeFi
Step 1. Get a non-custodial wallet. Metamask for Ethereum and EVM chains, Phantom for Solana. Backup the seed phrase on paper. Never share it. Detailed setup in our crypto storage guide.
Step 2. Buy crypto on a centralized exchange and withdraw to your wallet. ETH or SOL for gas fees, plus the asset you actually want to deploy (usually USDC for lending). See how to buy crypto.
Step 3. Connect your wallet to a top protocol. Aave for first-time lenders. Uniswap for first-time DEX swaps. Start with under 100 USD until you understand gas, slippage and the approval flow.
Step 4. Watch for two cost gotchas. Gas fees on Ethereum mainnet can be 5-50 USD per transaction during congestion - use Arbitrum, Optimism or Base for cheaper layer-2 versions of the same protocols. Slippage on small or new tokens can eat 5%+ of the trade.
Section 05 · Risks
Four risks that drain DeFi accounts
Smart contract exploit
Bug in the protocol code lets an attacker drain user funds. Over 3 billion USD lost in 2022 alone (Ronin, Wormhole, Beanstalk).
Stick to top-10 protocols with multiple audits and 2+ years live.
Impermanent loss
When you provide liquidity to a pool with two volatile tokens, price divergence makes you worse off than just holding. Affects most LP positions.
Stick to stablecoin LPs (USDC/USDT) where both sides hold value.
Rug pull / exit scam
New protocol launches with high yields, attracts deposits, the team drains the contract and disappears. Common in launch-week farms on smaller chains.
Avoid protocols under 6 months old, no audit, anonymous team, APY above 50%.
Oracle / depeg cascade
Lending protocols rely on price feeds (oracles). When a feed breaks or a stablecoin depegs, liquidations cascade and the protocol can go insolvent. UST/Anchor in 2022.
Spread across two protocols. Use only well-tested oracles (Chainlink).