You deposit stablecoins into a lending market, borrowers pay interest on what they take, and that interest flows back to you. That's the entire mechanism. The yield isn't fixed and it isn't magic — it moves with utilization, the share of deposited funds currently on loan.
How a lending pool converts your deposit into income
On Aave, every deposit of a given asset goes into one shared pool. Borrowers draw from that same pool. Your claim is tracked by an aToken, which grows in value as interest accrues — you don't claim anything manually, the balance just rises.
The interest rate comes from a formula, not a committee. Low utilization means cheap borrowing and thin supplier yields. High utilization pushes rates up, which pulls in more deposits and cools new borrowing. The curve does the job a loan officer would do at a bank, only continuously.
Why the supplier rate sits below the borrow rate
Part of what borrowers pay is diverted to the protocol's reserve factor. That slice stays in the pool as a buffer instead of being distributed. If borrowers pay 6% on a stablecoin, suppliers might see closer to 4–5%. The gap isn't a fee taken from your account — it's the protocol funding its own safety net.
Utilization in practice
Picture a USDC pool holding $10 million in deposits with $8 million borrowed. Utilization is 80%. Rates at that level are usually meaningfully higher than at 40%, but the pool also holds less idle liquidity for withdrawals. That trade-off matters more than the headline APY.
Rates move, and anyone quoting a fixed number is selling something
Stablecoin supply yields on major markets have historically swung between roughly 1% and double digits depending on the cycle. Quiet periods compress them. A large liquidation cascade, a flight to safety, or a new incentive program can spike them within days.
Anyone quoting you a fixed number for a variable-rate pool is either confused or selling something.
Incentives layered on base interest
Some markets add token rewards for suppliers, paid from a protocol treasury or a partner. These can change or disappear with little warning. Treat them as a bonus, never as the foundation of your return.
Looping, and where it breaks
You can deposit stablecoins, borrow against them, and redeposit the borrowed amount to stack yield. It's a real strategy, and it's also where people get hurt.
Run the scenario: you deposit 5,000 USDC, borrow 3,500 against it, and redeposit that 3,500. Total supplied is 8,500. If the supply rate is 5% and the borrow rate is 6%, you earn 425 on the supply side and pay 210 on the debt. Net, before incentives, that's 215 — against 250 from the original 5,000 alone. Looping only works when the supply rate exceeds the borrow rate, which is not the normal state of a stablecoin market. Worse, you've added liquidation risk to a negative spread.
Risks that don't show up in the APY number
Yield is the visible part. The rest is what you're actually being paid to accept.
- Smart contract risk. A bug or exploit can drain the pool. Audits reduce this. They don't eliminate it.
- Stablecoin risk. If the asset you supplied depegs, your aToken is worth less. No protocol can fix that.
- Liquidity risk. At very high utilization, you may not be able to withdraw everything immediately.
- Rate risk. Your yield can fall to near zero within days if borrowing demand disappears.
- Liquidation risk if you loop. A price move against your collateral can trigger a forced close.
None of these are reasons to avoid the strategy. They're reasons to size it like something that could go wrong.
Two approaches, side by side
| Approach | Typical yield source | Main risk |
|---|---|---|
| Simple supply | Borrower interest | Contract and stablecoin risk |
| Supply + borrow loop | Spread plus incentives | Liquidation, negative spread |
Start with the simple version. Looping is a tool for specific conditions, not a default.
Frequently asked questions
Is supplying stablecoins on Aave risk-free?
No. You're exposed to smart contract bugs, stablecoin depegs, and liquidity constraints during high utilization. The yield compensates you for taking those risks, which means the risk is real. Diversifying across protocols and assets reduces concentration but doesn't remove the underlying exposure.
Can I withdraw my stablecoins at any time?
Usually yes, but not always instantly. If utilization is very high, most of the pool is borrowed and there may not be enough idle liquidity for a large withdrawal until borrowers repay or new deposits arrive. Aave's rate model pushes rates up at high utilization specifically to encourage repayment.
Why is my yield lower than the borrow rate I see?
Borrowers pay more than suppliers receive because a portion goes to the protocol reserve. That reserve acts as a first-loss buffer. The gap you observe is that reserve factor at work, not a separate fee deducted from your account.
Should I loop my stablecoin position for higher yield?
Only when the supply rate genuinely exceeds the borrow rate, which is uncommon in stablecoin markets. Looping amplifies losses when the spread is negative and adds liquidation risk on top. Run the numbers with current rates before committing, and never assume the spread stays favorable.
Open the market you're considering, check the current supply rate and utilization side by side, and write down what your position would earn this week — before you deposit anything.