# Fixed and variable DeFi borrowing: which risk does a fixed rate remove?

Variable-rate borrowing accrues costs under a rate that can change with market conditions. Fixed-term borrowing sets an obligation tied to a maturity and execution price under its specific design. A fixed rate can make one cost more predictable, but collateral can still be liquidated and an early exit can depend on market liquidity.

Evidence: [LiquidityPool](https://aave.com/docs/aave-v3/concepts/liquidity-pool); [Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/)

Canonical: https://degreesofsatoshi.com/encyclopedia/fixed-variable-defi-borrowing/
Published: 2026-10-02
Substantively modified: 2026-10-02
Independently verified by an automated reviewer: 2026-10-02T19:18:00.092Z
Data current through: 2026-10-02

AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied.

## Key facts

- **Variable:** Aave supply and borrowing rates respond to pool conditions. ([LiquidityPool](https://aave.com/docs/aave-v3/concepts/liquidity-pool))
- **Fixed term:** Morpho Midnight trades units representing loan-token obligations at maturity. ([Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/))
- **Early exit:** The documented fixed-term design depends on secondary liquidity for early trading exits. ([Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/))

## Translate a discount into a period cost

In a simplified fixed-term example, a borrower receives 970 loan tokens now and owes 1,000 at maturity. The 30-token difference is about 3.093% of the 970 received for that term, before fees. It is not 3% of the amount received, and it is not an annual rate unless the term and annualization method justify that label.

A variable loan’s total cost instead depends on the path of its rates and balances.

Evidence: [Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/)

## A due date changes the operational obligation

The Midnight documentation says unpaid debt can be liquidated after maturity, while collateral health can trigger liquidation earlier. A borrower therefore needs both an ongoing collateral plan and an understanding of repayment timing. Fixed does not mean indefinite.

Evidence: [Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/)

## Compare the full obligation

Use the same debt asset, term and fee assumptions. For an early exit, inspect actual offers rather than assuming the original rate is available in reverse. Lenders also face the collateral and loss-allocation rules of the selected fixed-term market.

Evidence: [Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/); [LiquidityPool](https://aave.com/docs/aave-v3/concepts/liquidity-pool)

## Questions

### Does a fixed borrowing rate prevent liquidation?

No. It fixes a pricing feature of the obligation, not the future value of its collateral.

Evidence: [Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/)

## Claims and scope

### fixed-variable-defi-borrowing-quick-answer

Variable-rate borrowing accrues costs under a rate that can change with market conditions. Fixed-term borrowing sets an obligation tied to a maturity and execution price under its specific design. A fixed rate can make one cost more predictable, but collateral can still be liquidated and an early exit can depend on market liquidity.

Scope: {"collection":"defi","dataAsOf":"2026-10-02","blockHeight":null}

### fixed-variable-defi-borrowing-fact-variable

Variable: Aave supply and borrowing rates respond to pool conditions.

Scope: {"collection":"defi","dataAsOf":"2026-10-02","blockHeight":null}

### fixed-variable-defi-borrowing-fact-fixed-term

Fixed term: Morpho Midnight trades units representing loan-token obligations at maturity.

Scope: {"collection":"defi","dataAsOf":"2026-10-02","blockHeight":null}

### fixed-variable-defi-borrowing-fact-early-exit

Early exit: The documented fixed-term design depends on secondary liquidity for early trading exits.

Scope: {"collection":"defi","dataAsOf":"2026-10-02","blockHeight":null}

## Sources

- [LiquidityPool](https://aave.com/docs/aave-v3/concepts/liquidity-pool) — Aave. Pooled supply/collateral interest and repayment asset. Locator: Supply; Borrow; Repay. Retrieved: 2026-10-02T18:53:21.761Z.
- [Fixed Rate Markets (Midnight)](https://docs.morpho.org/developers/midnight/get-started/) — Morpho. Dated documentation example of fixed-term lending mechanics, not an availability guarantee. Locator: Fixed-rate model; maturity; risks. Retrieved: 2026-10-02T18:53:22.486Z.

## Revision history

- 2026-10-02: First publication after primary-source research and separate automated verification.

## Cite this entry

Degrees of Satoshi editorial project. “Fixed and variable DeFi borrowing: which risk does a fixed rate remove?.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/fixed-variable-defi-borrowing/