BaseJumpRateModelV2

Logic for Compound's JumpRateModel Contract V2.

An interest rate model with a steep increase after a certain utilization threshold called kink is reached. This rate model uses the following formula for the borrow rate:

• $borrow\_rate(u)=a_1 \cdot u + b$, when $u < kink$

• $borrow\_rate(u)=a_1 \cdot kink + a_2 \cdot (u-kink) + b$, otherwise

The parameters of this interest rate model can be adjusted by the owner. Version 2 modifies Version 1 by enabling updateable parameters.

Solidity API

accessControlManager

The address of the AccessControlManager contract

contract IAccessControlManagerV8 accessControlManager

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multiplierPerBlock

The multiplier of utilization rate that gives the slope of the interest rate

uint256 multiplierPerBlock

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baseRatePerBlock

The base interest rate which is the y-intercept when utilization rate is 0

uint256 baseRatePerBlock

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jumpMultiplierPerBlock

The multiplier per block after hitting a specified utilization point

uint256 jumpMultiplierPerBlock

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kink

The utilization point at which the jump multiplier is applied

uint256 kink

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updateJumpRateModel

Update the parameters of the interest rate model

function updateJumpRateModel(uint256 baseRatePerYear, uint256 multiplierPerYear, uint256 jumpMultiplierPerYear, uint256 kink_) external virtual

Parameters

Name	Type	Description
baseRatePerYear	uint256	The approximate target base APR, as a mantissa (scaled by EXP_SCALE)
multiplierPerYear	uint256	The rate of increase in interest rate wrt utilization (scaled by EXP_SCALE)
jumpMultiplierPerYear	uint256	The multiplierPerBlock after hitting a specified utilization point
kink_	uint256	The utilization point at which the jump multiplier is applied

⛔️ Access Requirements

• Controlled by AccessControlManager

❌ Errors

• Unauthorized if the sender is not allowed to call this function

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getSupplyRate

Calculates the current supply rate per block

function getSupplyRate(uint256 cash, uint256 borrows, uint256 reserves, uint256 reserveFactorMantissa, uint256 badDebt) public view virtual returns (uint256)

Parameters

Name	Type	Description
cash	uint256	The amount of cash in the market
borrows	uint256	The amount of borrows in the market
reserves	uint256	The amount of reserves in the market
reserveFactorMantissa	uint256	The current reserve factor for the market
badDebt	uint256	The amount of badDebt in the market

Return Values

Name	Type	Description
[0]	uint256	The supply rate percentage per block as a mantissa (scaled by EXP_SCALE)

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utilizationRate

Calculates the utilization rate of the market: (borrows + badDebt) / (cash + borrows + badDebt - reserves)

function utilizationRate(uint256 cash, uint256 borrows, uint256 reserves, uint256 badDebt) public pure returns (uint256)

Parameters

Name	Type	Description
cash	uint256	The amount of cash in the market
borrows	uint256	The amount of borrows in the market
reserves	uint256	The amount of reserves in the market (currently unused)
badDebt	uint256	The amount of badDebt in the market

Return Values

Name	Type	Description
[0]	uint256	The utilization rate as a mantissa between [0, MANTISSA_ONE]

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