DeFi Lending Explained: How to Earn Interest on Crypto
DeFi lending replaces banks with smart contracts. You supply crypto, borrowers pay interest, and you earn a share — all without intermediaries. Here's how it works.
The Two Sides of DeFi Lending
Supplying (Lending)
You deposit crypto into a lending pool. Borrowers pay interest. You earn a proportional share of that interest plus any protocol rewards.
Borrowing
You post crypto as collateral and borrow other assets. No credit check — the collateral secures the loan. Interest accrues until you repay.
How Interest Rates Work
Rates are set algorithmically based on utilization:
- Low utilization — few borrowers, low rates (attracts borrowing)
- High utilization — most of the pool is borrowed, rates spike (attracts deposits)
Typical rates (2026): USDC lending 4-8% APY, ETH lending 2-5%, exotic tokens can hit 20%+ but with much higher risk.
Top DeFi Lending Platforms
Aave
The largest lending protocol. Multi-chain. Supports dozens of assets. Battle-tested codebase.
Compound
Pioneer of DeFi lending. Simple interface. Focused on Ethereum and L2s.
Morpho
Optimizes rates by matching lenders and borrowers directly. Growing fast in 2026.
The Key Risk: Liquidation
Example: You deposit $1,000 of ETH and borrow $500 USDC (150% collateral ratio). If ETH drops 30%, your collateral is now $700 — close to the liquidation threshold. If ETH drops further, the protocol auto-sells your ETH to repay the loan, and you lose most of your position.
Understanding Health Factor
Every borrower has a health factor. Above 1.0 = safe. Below 1.0 = liquidation.
- Health > 2.0 — very safe
- Health 1.5-2.0 — safe but watch closely
- Health 1.1-1.5 — risky, monitor constantly
- Health < 1.1 — danger zone, add collateral or repay
Strategy: Stablecoin Lending
For most beginners, the safest approach:
- Supply USDC or USDT to Aave
- Earn 4-8% APY with no liquidation risk (you're not borrowing)
- Withdraw anytime
This is similar to a high-yield savings account — but the risk is smart contract failure, not bank failure.
Risks to Understand
- Smart contract bugs — even audited protocols can fail
- Liquidation risk — if you borrow, monitor health factor constantly
- Stablecoin depeg — if USDC drops to $0.95, you lose real value
- Protocol risk — newer platforms carry higher risk
- Gas fees — Ethereum transactions can be expensive
Getting Started
- Set up a wallet (MetaMask)
- Fund with USDC from a CEX
- Connect to Aave at app.aave.com
- Supply a small amount first ($50-100) to learn the interface
- Track your earnings weekly
- Scale only after understanding the mechanics
Frequently Asked Questions
What is DeFi lending?
Supplying crypto to earn interest, or borrowing by posting collateral. All on-chain via smart contracts.
How much can you earn?
Stablecoins usually 4-8% APY. Volatile assets can earn more but carry more risk.
What is liquidation risk?
If you borrow, and collateral drops below threshold, protocol auto-sells your collateral. Always monitor your health factor.