DeFi Lending Basics
Supply crypto to protocols to earn interest. Borrow against holdings for leverage or liquidity.
Popular Protocols
- Aave: Multi-currency lending
- Compound: Algorithmic rates
- Maker: DAI stablecoin creation
- Cream: Permissionless lending
How Borrowing Works
Deposit collateral (e.g., ETH), borrow stablecoins. Maintain collateral ratio above liquidation threshold.
Strategies
- Supply stablecoins for consistent yield
- Borrow against holdings for tax efficiency
- Loop deposits for leveraged exposure
Risks
- Liquidation if collateral ratio drops
- Smart contract vulnerabilities
- Interest rate volatility
DeFi Lending: How Supply Meets Borrowers
Borrowing in DeFi is collateralised lending: lenders supply stablecoins into a pool and earn the utilisation-linked rate, while borrowers lock crypto collateral (often 150%+) and pay an annualised borrowing rate. The pool algorithm re-prices every block, so lenders see variable returns and borrowers see a live cost of funds. The key sanity check is the utilisation ratio - if everyone deposits and nobody borrows, the lender's yield collapses toward zero until rates rebalance. Understanding this one ratio explains most DeFi yield dynamics.
Liquidation Mechanics: The Borrowers' Reality
Collateral is monitored continuously, not daily. If the loan's health factor falls below the protocol's threshold, liquidators take over the collateral at a discount - the borrower loses assets, the lender gains an interest boost, and the protocol keeps the incentive architecture funded. This is why borrowers must over-collateralise generously and log a manual top-up routine before volatility spikes; a 2% overnight move can be far bigger than the borrower's buffer.
The Depositor's Yield Formula
Earned APY ≈ base pool APR + reward tokens (often the protocol's own)
Real value = (stablecoin yield) - (emission dilution) - (gas) - (risks)Depositors who only read the headline APY miss the dilution side: when the "yield" is printed in the protocol token, the true value is what remains after the token's market value drops with the emission. Saving in stablecoins on a reputable protocol while mentally discounting every reward token is the realistic way to treat such yields.
DeFi Lending and Borrowing Risks
- Smart-contract and oracle risk - the collateral price feed can be manipulated or lag, triggering false liquidations
- Liquidity risk during a crisis - lenders may not be able to withdraw when utilisation spikes
- Depeg risk - a "stablecoin" that loses its peg breaks every assumption of the deposit
- Liquidation cascades - correlated collateral drops force simultaneous liquidations that pressure prices further
A Practical Indian Filter
For an Indian investor the filter is stricter: check regulatory standing of the protocol's jurisdiction, currency-conversion and tax treatment of reward tokens, gas costs on the chosen chain, and whether the protocol has survived a genuine stress event. A lending position you cannot explain, monitor, and exit quickly is a risk compound, not a yield.
Bottom Line
DeFi lending rewards the studious: supply stablecoins, monitor utilisation, understand liquidation maths for borrowers, discount emission-based rewards, and never chase an APY you cannot narrate in two sentences.
Utilization, Supply APY, and the Rate Curve
Every lending protocol adjusts its interest rate dynamically around a single variable: utilisation, the share of deposited capital currently lent out. Keep utilisation at 40 to 60 percent and the pooled protocol earns a healthy margin while lenders enjoy stable rates; push utilisation above 90 percent and the borrow rate climbs steeply to draw fresh deposits, which is exactly the mechanism that protects solvency at the cost of rate volatility. Read a protocol's black-box curve before depositing. A stablecoin lending pair quoting 5 percent at 50 percent utilisation and 30 percent at 95 percent tells you more than the headline APY banner.
The Depositor's Real Return
The displayed supply APY is revenue before your true costs: bridge fees on whatever network you enter through, the spread on depositing a stablecoin, and the risk of the pooled asset itself. On an Indian execution flow, enter through a major network with the asset already in your own wallet, keep the collateral on one conversation, and recognise that a 6 percent nominal APY nets closer to 4.5 percent after realistic fees. That single adjustment sets expectations that survive contact with the market.
Collateral Factors and Loan-to-Value Ladders
Borrowing works because the protocol prices risk as collateral factor. A top stablecoin may carry a 90 percent collateral factor, meaning you can borrow 90 rupees per 100 rupees deposited; a volatile alt sits nearer 50 percent, and a blue-chip can rest in between. Treat the published liquidation threshold as an absolute, not a suggestion: the protocol liquidates whenever utilisation passes the threshold, and it does so automatically against your collateral at a steep penalty. Borrow only to the 60 to 70 percent of the collateral factor, never to the cap, because a 5 percent adverse move then cannot trigger the cascade.
A Worked Stablecoin Borrow
Deposit 10,000 rupees of USDT on a 75 percent collateral factor and you can draw roughly 7,000 to 7,500 rupees of the paired stablecoin. The borrowed yield targets a low-volatility farm paying 8 to 12 percent, and the deposit side still earns supply interest on the full 10,000. The gap between the borrow cost and the farm yield is your carry. If the farm drops from 10 percent to 6 percent while the borrow costs 4 percent, the spread collapses and the position stops earning; exit it with arithmetic, not hope, the moment the net carry turns negative after fees.
The Risks Regulators Forgot to Name
Lending risk is not one risk but a stack. Smart-contract risk is the headline, but the daily reality for retail is smart money velocity: yield chasers rotate into whichever pool pays, leaving the previous pool's lenders holding a thinning book at a falling rate. Oracle risk is real too, because a manipulated price feed liquidates positions instantly on chains where the pool is the majority of its own liquidity. And an Indian user faces a compliance boundary most guides skip: deposits and borrows are taxable events, and the 30 percent plus cess structure applies to any gain realised on these positions.
- Read the protocol's utilisation curve before depositing.
- Guard the borrow to no more than 70 percent of the collateral factor.
- Net the carry after bridge fees and spreads, never the headline APY.
- Keep a withdrawal plan for the pool's per-user cap.
- Log every deposit and swap for Indian tax records.
Stablecoin Choice and Depeg Risk
The collateral you deposit is an asset, not a number: a stablecoin's own stability is the floor under the whole lending book, and a depeg converts "safe" collateral into a liquidating trigger on the protocol side. Prefer the largest, battle-tested stablecoins for collateral and yield, treat algorithmic stablecoins as a different risk class entirely, and read the collateral's deployment history before trusting the advertised APY. The second leg of the audit is the protocol itself: verify the smart contracts were reviewed by a named firm, check how recent the review is, and confirm whether a pause or emergency-withdrawal mechanism exists. A lending position is only as calm as its remotest dependency, and the dependency tree - token, pool, oracle, protocol - belongs on the same page as the APY.
