Borrowed 1,530 USDC, but when it matures, you have to repay 1,600 USDC.

That 70-dollar difference is the actual borrowing cost.
Many protocols only give you a simple interest rate figure, @TermMaxFi directly breaks this cost into an asset called XT.
It will inevitably expire to zero, but precisely this point allows people to truly understand their fixed interest rate mechanics.
TermMax splits a fixed-term debt into three accounts:
GT is the borrower's NFT position, recording what you collateralized and how much you owe in total;
FT is the lender's maturity payout right, bought at a discount today and redeemed at face value at maturity;
XT specifically records the interest cost that hasn't been paid from today until maturity.
Simply put, GT is the IOU, FT records the future money, and XT tracks the remaining time.
The three are tightly bound: 1 FT + 1 XT = 1 debt token.
For example, with a one-year fixed rate of 8%, 1 FT's present value is about 0.926 USDC, 1 XT is about 0.074 USDC, totaling exactly 1 USDC.
It's not about predicting prices but breaking down the debt to see clearly: 0.926 is the present value of the future principal, and 0.074 is the interest obligation corresponding to the time.
The most counterintuitive part of XT is that its normal path is to decay all the way to zero.
As maturity approaches, FT gets closer to full face value, and XT decreases.
Using the above example, when half a year remains, XT is roughly only 0.037, and at maturity, it completely expires to zero.
Many ask, why does something that will definitely expire to zero need to exist?
The answer lies in those three words: knowing in advance.
Yesterday, you could calculate a year's interest; half a year later, only half remains; on the day of maturity, the time value is completely exhausted.
If XT doesn't expire to zero, the same debt would be counted twice, and the accounts wouldn't match.
So, expiring to zero isn't a bug but solid proof that the settlement is complete.
From the borrower's perspective, Alice locks 2 ETH, GT records a 1,600 USDC debt, and she actually receives 1,530 USDC.
That 70 is the cost of locking in funds early.
GT remembers how much to repay, FT is handed to the lender, and XT reflects why less was received today in terms of price.
In the contract, FT and XT can still be combined and exchanged, but the economic result remains the same: you pay a bit more in the future, or get immediate usable funds today.
In the past, the community often only discussed FT and GT—one fixed income, one leveraged position.
Without XT, there's a missing piece: how to price the element of time.
And the core of fixed interest rates is precisely the time value.
XT isn't just a regular worthless token, nor should it be forced into traditional options; it first and foremost is a true record of the remaining debt time.
Now, TermMax V2 brings order, position, and exposure information to the forefront, with a clearer interface.
Everyone should understand the underlying logic: FT moves toward redemption, XT moves toward zero, and GT retains a complete debt record.
Once these three lines are complete, a fixed-rate loan truly forms a closed loop.
Of course, risks still exist—fixed costs are fixed, but collateral prices, liquidations, oracles, liquidity, and smart contract risks are all present.
Mechanically, it clarifies that fixed interest isn't about guessing the future but about breaking down principal, cost, and time into separate accounts in advance.
An asset destined to expire to zero but indispensable—do you see it as a risk, or as a countdown to interest?
Feel free to discuss—what's your take on this XT design?