What is a Collateral Factor?
The collateral factor (also called the loan-to-value (LTV) ratio or collateralization ratio) is the parameter a lending protocol uses to decide how much you can borrow against a given asset. If an asset has a 75% collateral factor, then for every $100 of that asset you deposit as collateral, you may borrow up to $75 against it. The remaining 25% is a safety buffer that protects the protocol from becoming undercollateralized if the asset’s price drops.
Collateral factors are the central risk-management knob in overcollateralized lending protocols like Aave, Compound, and Maker. Set them too high and a normal price swing will trigger a cascade of liquidations (or worse, leave the protocol with bad debt); set them too low and the protocol becomes unattractive to borrowers. Each asset gets its own factor, calibrated to its volatility and liquidity.
How the Collateral Factor Works / Technical Details
The Borrowing Capacity Calculation
A protocol computes your total borrowing power as the sum of (deposit value × collateral factor) across all your collateral assets:
- Deposit 10 ETH at $2,000 = $20,000, with a 75% factor → $15,000 of borrowing power
- Deposit 10,000 USDC with a 95% factor → $9,500 of borrowing power
- Total borrowing power: $24,500
You can borrow up to that aggregate limit in any supported asset. As soon as your outstanding debt exceeds your borrowing power, your position becomes eligible for liquidation.
The Health Factor
Most protocols express your safety margin as a health factor:
Health Factor = (Collateral Value × Collateral Factor) / Borrowed Value
- Above 1.0 — safe
- Exactly 1.0 — at the liquidation threshold
- Below 1.0 — liquidatable
A falling asset price (or rising borrowed asset price) shrinks your numerator, pushing the health factor toward 1.0. Sophisticated borrowers watch this number closely and either add collateral or repay debt to keep a comfortable buffer.
Why Different Assets Have Different Factors
| Asset Type | Typical Factor | Rationale |
|---|---|---|
| Blue-chip stablecoins (USDC, USDT) | 80–95% | Low volatility, deep liquidity |
| ETH / WBTC | 70–82% | Moderate volatility, deep liquidity |
| Major governance tokens (UNI, AAVE) | 50–70% | Higher volatility, still liquid |
| Long-tail / volatile tokens | 20–50% | High volatility, thin liquidity, hard to liquidate |
| Staked / yield-bearing assets (stETH) | 70–80% | Slight depeg/withdrawal risk |
The principle: the more volatile and less liquid an asset, the lower its factor, because a price drop would otherwise outpace the protocol’s ability to liquidate.
Notable Examples and Incident Vectors
MakerDAO’s Safe System Parameters
MakerDAO popularized granular, per-collateral risk parameters managed by decentralized governance. Each collateral type has a “stability fee,” a liquidation ratio (their collateral-factor equivalent), and an auction system. Governance constantly tunes these as market conditions change — for example, lowering the ratio for volatile collateral during stress.
Liquidation Cascades
When a volatile asset’s price drops sharply, many positions hit their collateral factor simultaneously. Liquidators sell the collateral to repay debt, which can push the asset’s price down further (especially for illiquid tokens), triggering more liquidations — a cascade. Collateral factors are set with a buffer specifically to give the protocol room to liquidate before the position becomes underwater. When the buffer is too thin (high factor on a volatile asset), cascades produce bad debt — positions where the collateral is worth less than the debt even after liquidation.
Oracle + Collateral Factor Interaction
The collateral factor only works if the price the protocol reads is accurate. If an oracle reports a stale or manipulated price, the computed health factor is wrong. A flash-loan-driven oracle manipulation can briefly inflate a token’s price, letting an attacker borrow far more than the collateral is truly worth, then leave the protocol with bad debt when the price corrects. This is why collateral factors for thin tokens are kept low and why protocols favor robust oracle designs.
How to Use Collateral Factors Wisely
For Borrowers
- Stay well below the limit. A health factor of 1.0 is the cliff, not the target. Maintain a buffer (e.g., health factor > 1.5) so normal volatility doesn’t liquidate you.
- Understand liquidation penalties. When liquidated, you lose collateral plus a penalty (often 5–15%) that goes to the liquidator. Repeated near-threshold borrowing is expensive.
- Beware correlated collateral and debt. If you deposit ETH and borrow ETH-pegged or ETH-correlated assets, a price drop hurts both sides at once, collapsing your health factor faster than you’d expect.
- Monitor in real time. Use alerts; liquidations can happen in seconds during volatility.
For Protocol Designers
- Calibrate factors conservatively based on worst-case historical drawdowns and liquidation-depth analysis, not typical volatility.
- Stress-test for cascades and oracle failures.
- Adjust dynamically through governance when market conditions change.
Frequently Asked Questions
Q: What’s the difference between collateral factor and loan-to-value (LTV)? A: They describe the same idea from opposite directions. Collateral factor is the protocol-set maximum borrowing percentage (e.g., 75%). LTV is your actual borrowing as a percentage of collateral (e.g., if you borrowed $50 against $100, your LTV is 50%). You get liquidated when your LTV exceeds the collateral factor.
Q: Can the collateral factor change while I have a loan? A: Yes. Governance can lower an asset’s factor at any time, which reduces your borrowing power and could push an existing position into liquidation. Always account for parameter-change risk.
Q: What happens to my collateral when I’m liquidated? A: A liquidator repays part of your debt and takes an equivalent (plus penalty) amount of your collateral. The penalty incentivizes fast liquidation, which protects the protocol from bad debt.