Interest

The rate model

Every market charges borrowers a rate that depends on how much of its pool is lent out, its use:

So the rate runs from 5% a year in an untouched pool to 20% in a fully lent one. All three markets launch with the same model; each market's pool is separate, so their rates differ.

How debt grows

Debt grows every second. The program keeps a debt index for each market and compounds it per second at the current rate whenever an instruction touches the market. Your loan holds debt shares; what you owe is your shares times the index, rounded up.

Because the rate depends on use at the moment of each update, it changes as people borrow, repay, deposit and withdraw. The app shows your debt ticking up in real time.

As an example, 9,000 USDC borrowed for 30 days at a steady 14% a year grows by about 104 USDC.

What lenders earn

A lender's shares are a claim on the pool: its idle cash plus what borrowers owe. Interest raises what borrowers owe, so each share is worth more over time. Since only lent dollars earn, lenders as a whole earn about the borrow rate times the use. At 60% use, borrowers pay 14% and lenders earn 8.4%.

The program keeps no share of interest. Band trade fees are separate: they stay in the bands and belong to the borrowers who own them.