Lend

Interest rates

One kinked curve sets the borrow rate from utilization. Lenders earn the borrow rate times utilization. The curve is fixed when the pool is created.

The live pool

The pool's live rates appear here once Yoke is live. The curve itself is described below.

Utilization

utilization = debt ÷ (cash + debt)

debt is everything credit accounts owe, interest included, and cash is the USDC sitting in the pool's vault.

Borrow rate

The curve has a base rate, a first slope up to the kink, and a steeper second slope above it:

below the kink:  rate = base + slope₁ × utilization ÷ kink
above the kink:  rate = base + slope₁ + slope₂ × (utilization − kink) ÷ (1 − kink)

Rates are yearly and in basis points. The pool is created with its four parameters and they can't change afterwards. The kink has to sit strictly between 0% and 100%, and no curve may reach above 300% a year.

Supply rate

supply rate = borrow rate × utilization

The pool keeps nothing for itself. Every unit of interest raises the value of lenders' shares.

How interest accrues

Each instruction that touches the pool first brings it up to date: it multiplies the debt index by the rate for the seconds since the last update, rounded up. Accrual between updates is simple; across updates it compounds. The time comes from the chain's clock, and the program refuses to run if it would go backwards.

Next

• LendSupplying USDCDeposit USDC into the pool for shares, earn the interest credit accounts pay, and withdraw against the pool's cash.
• ProtocolParametersEvery number the program enforces, in one place. Weights, the buffer and the premium are compiled in; the rate curve is set once per pool.