Fixed-Rate Lending: Market Structure and Protocol Design
A report on the protocols building fixed-rate and fixed-maturity credit products
Data snapshot: August 2026. Figures are preserved from the published report and are not live market data.
“Fixed rates do not remove any risk that variable-rate lending has uncovered over the years, but they make the cost of debt explicit.”
▮ The numbers that matter
Executive Summary
DeFi lending supports $28.5 billion in active loans, but almost all demand remains in variable-rate markets. The report compares fixed-rate and fixed-maturity designs that make borrowing costs explicit while addressing fragmented liquidity, idle capital and early exits. It covers incumbent-led models from Morpho, Jupiter and Kamino alongside purpose-built markets including Term Labs, TermMax, Fira, Loopscale, Liquity, Flex and IRIS Credit.
Key findings
- 01DeFi lending had $28.5 billion in active loans at the report snapshot, with almost all demand still served by variable-rate markets.
- 02Morpho Midnight uses tradable credit and debt units to improve early exits and had reached $3 million in active loans after its July launch.
- 03Jupiter Offerbook had reached $450,000 in active loans using fixed terms of one to 30 days and maturity-based collateral transfer instead of continuous liquidation.
Covered in the report
Inside
- 01Introduction
- 02Different Answers to the Same Credit Problem
- 03Variable-Rate Incumbents Entering Fixed-Term Markets
- 04Purpose-Built Fixed-Rate Credit Markets
- 05Emerging Models for Predictable Credit
- 06Curator-Built Fixed-Rate Markets
- 07Closing Thoughts
Method and Data Boundary
Castle compares protocol design, liquidity formation, maturity handling and exit mechanics across incumbent and purpose-built fixed-rate markets. The analysis combines interviews with Morpho, Tenor Finance, Term Labs and IRIS Credit with protocol documentation and lending balances from DeFiLlama around publication.
- Published
- August 2026
- Data snapshot
- August 2026