Lending has long been one of DeFi’s most important building blocks. By putting collateral, borrowing, and liquidation rules into public smart contracts, it makes fund flows and debt positions easier to verify and allows assets to connect with different financial applications.
As we enter 2026, fixed-rate lending is becoming a new focus of DeFi development. This direction did not appear suddenly. As early as 2020, Yield Protocol and Notional Finance had already successively tried to introduce fixed-rate, fixed-term structures on-chain. In 2024, Term Labs being selected for a16z CSX showed that primary-market interest in these structures has not faded. Now, Morpho has launched the fixed-rate protocol Midnight in addition to its floating-rate market Morpho Blue.
These efforts address a real need: borrowers want to know how much interest they will owe before putting borrowed capital to work.
But fixing the rate does not necessarily align the needs of borrowers and lenders. How long the borrower actually needs the money, how early repayment is calculated, and how the lender can put returned capital back to work still determine whether a loan is worth making.
Launchpool: Price Risk or Borrowing Rate Risk
Consider the familiar Binance Launchpool scenario.
The most straightforward approach is to buy BNB and use it to participate. But if the market has already bought ahead of the event and pushed prices higher after the announcement, later participants face a higher entry cost. If BNB falls as the event draws to a close, the new tokens earned may not cover the loss on buying and selling BNB.
That leads to another approach: pledge other assets as collateral, borrow BNB for the event, and repay it afterward.
Venus has served this type of demand. Users do not have to buy BNB outright, but they face another bill that can change while the strategy is running: borrowing interest.
Protocols such as Maker, Aave, and Venus helped make onchain financing widely accessible, but borrowing costs were not necessarily locked in when a position was opened. Variable borrowing rates on Aave and Venus respond to the supply and demand for capital; Maker’s stability fees can also change through governance.
Take a hypothetical example. A user borrows BNB at an annual rate of 2%. Once the event begins, borrowers flood in and the rate rises to 6%, or even 7%. If the value of the rewards only covers the interest accrued during the event, there may be little profit left after all that effort. Historical analysis published in the Venus community has also documented sharp increases in BNB borrowing demand and rates when Launchpool events begin.
The same problem arises in staking, arbitrage, and LP farming. A user borrowing stablecoins for USDC/USDT LP farming earns whatever remains after funding costs are deducted from trading fees, incentives, and other returns. For a strategy with an expected annualized net spread of just 1–2 percentage points, an equivalent rise in the borrowing rate can wipe out the entire margin.
Users can budget for rate volatility. But if the necessary buffer consumes the expected profit, the rational decision may be not to borrow at all.
This is the appeal of fixed-rate lending: determine the interest cost first, then decide whether the opportunity is worth pursuing. Strategy returns can still change, but at least one moving variable on the cost side has been removed.
The Rate Fits. The Borrowing Period Doesn’t.
Suppose a user joins a 7-day Launchpad event. By day 7, the event has ended, the position is unwound, and funds are available for repayment.
Yet no suitable seven-day quote was available at entry. The financing came from a fixed-rate market maturing in 30 days.
A fixed-maturity loan establishes the amount owed at maturity when the trade is executed. Keeping it until maturity makes the interest bill predictable. But this borrower needs only 7 days. What happens to the remaining 23?
In one type of fixed-maturity debt design, the borrower can repay the full face value early. The amount is known, but early repayment does not automatically remove the cost of unused days.
Alternatively, the borrower can buy corresponding credit units on the secondary market to offset the debt. Rising market rates typically reduce existing credit prices, potentially making a buyback cheaper; falling rates can make it more expensive. Execution also depends on available quotes and liquidity.
The original rate remains fixed. But the final cost of a market exit on day 7 cannot be precisely locked in on day 1.
The choice is between a known financing cost covering more time than needed and an early exit priced by the market.
Capital is available, but the borrower’s actual need may still be unmet.
Some fixed-rate designs leave this gap open. Borrowers want to know more than what they owe after one hundred days: can they use the funds for seven days and pay the original rate for those seven days alone?
Use It for 7 Days, Pay for 7 Days
Constant Finance is building a lending mechanism to address this mismatch.
According to the team, the fixed rate and early repayment rules are agreed when the loan is made. Within the contract’s permitted period, borrowers can repay principal early, settle interest at the original rate for the time used, and stop further interest accrual.
For unchanged principal and simple interest:
Interest = Principal × Agreed Annual Interest Rate × Actual Days Borrowed ÷ Agreed Number of Days per Year.
7 days of use means 7 days of interest. Borrowers do not need to wait until day seven to find an exit price based on market rates.
A contract with a later maturity can therefore serve a shorter funding need, provided the lender accepts early repayment. That flexibility is agreed upfront.
For the Launchpad participant, seven days of interest can be calculated before deciding to join. An opportunity rejected because of an unsuitable term or uncertain exit cost can become worth considering again.
When One Loan Ends, Capital Can Find Another Match
Borrower flexibility also needs to work for lenders. A loan ending early does not necessarily have to end a longer lending plan.
Under Constant Finance’s design, returned capital is immediately rematched if the original lending order remains active and sufficient executable borrowing orders meet the lender’s conditions. Each new loan accrues interest on its own agreed terms.
Capital available for a longer period can serve a 7-day need, return, and fund another borrower. Successive matches connect short-term demand with a longer lending plan.
This still requires suitable demand. After market rates fall, some capital may wait if borrowing demand is insufficient at the lender’s existing terms. Lenders must account for early repayment and reinvestment when quoting. Their minimum rate sets acceptable terms for the next loan; it does not guarantee returns while funds are waiting.
Borrowers pay for the time they use the funds. Lenders seek the next loan on terms they accept. Both can participate under mutually acceptable rules.
Making Loans Possible That Would Otherwise Never Happen
A market can have available capital and willing borrowers yet fail to produce a transaction both sides accept.
An opportunity may last seven days while financing requires paying for much longer. Or the rate looks attractive, but the early exit price will only be known later. Such borrowing needs can disappear before an order is placed.
Fixed-rate lending’s progress should also be measured by these unmet needs. Connecting rates, actual borrowing periods, early repayment, and the reuse of returned capital can bring funding closer to its intended purpose.
Constant Finance aims to make that connection: matching both sides’ conditions more closely so that some loans that would otherwise never happen become possible.
About Constant Finance
Constant Finance is building fixed-rate, fixed-term lending infrastructure for decentralized finance. Its product enables borrowers and lenders to select an interest rate and maturity in advance and includes built-in refinancing when financing needs change.
Learn more at https://www.constant.finance/ and follow Constant Finance on X.
