# Interest rate

## Platform borrow and deposit interest rate

* Borrow Interest = m × fund utilization rate + b

### Rates table for tokens

| Token | baseRate | 80% | 90%  | 100% |
| ----- | -------- | --- | ---- | ---- |
| HT    | 10%      | 20% | 25%  | 50%  |
| BTC   | 10%      | 20% | 25%  | 50%  |
| ETH   | 10%      | 20% | 25%  | 50%  |
| HPT   | 10%      | 20% | 25%  | 50%  |
| HFIL  | 10%      | 20% | 25%  | 50%  |
| DOGE  | 10%      | 20% | 25%  | 50%  |
| USDT  | 13%      | 25% | 30%  | 60%  |
| HUSD  | 13%      | 25% | 30%  | 60%  |
| MDX   | 50%      | 80% | 100% | 150% |
| BXH   | 50%      | 80% | 100% | 150% |

![BACK Interest vs Utilization](https://586441834-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MVUR8IbdmrBuFd8qJDS%2Fsync%2Fee0228f4e934dca53861ad5eb79893683f6b7d15.png?generation=1618890869718147\&alt=media)

* Deposit APR = (1 - interest retention ratio) × fund utilization rate × borrow interest rate

Take deposit pool `10,000,000` `USDT` as an example. The interest retention ratio is 10%. When the borrowed amount is `5,000,000`, `8,000,000` and`9,500,000` respectively, the borrow and deposit interest rate are showed as follows:

| Fund utilization rate | Borrow Interest/annual borrow interest | Deposit APR/annual deposit interes |
| --------------------- | -------------------------------------- | ---------------------------------- |
| 50% (lend`5,000,000`) | 16.25% / `812,500`                     | 7.3125% / `731,250`                |
| 80% (lend`8,000,000`) | 20% / `1,600,000`                      | 14.4% / `1,440,000`                |
| 95% (lend`9,500,000`) | 55% / `5,225,000`                      | 47.025% / `4,702,500`              |

## Leveraged mining composite APY

**Leveraged mining APY = Yield farm income (compound interest) × leverage ratio - (leverage ratio - 1) × Borrow Interest + (leverage ratio - 1) × Platform mining income**

* Liquidity mining income = (platform token per block of liquidity mining pool × latform token price / total asset value of the pool) × 10512000
* Yield farm income (compound interest)=(1 + Liquidity mining income/365)^365 - 1
* Platform mining income = (BACK produced per block of liquidity mining pool × BACK current price / total loan value of the pool) × 10512000
* Borrow Interest = m × fund utilization rate + b

> Note: BACK per block of liquidity mining pool = BACK per block × BACK pool reward weight × BACK borrower weight.
>
> Note: 10512000 is the number of output of HECO chain every year.

## Deposit composite APR

**Deposit composite APR = deposit APR + platform deposit reward APR**

* Deposit APR= (1 - interest retention ratio) × fund utilization rate × borrow interest rate
* Platform deposit reward APR = (BACK produced per block of deposit pool × BACK price / total value of deposit) × 10512000

> Note: BACK per block of deposit pool = BACK per block × BACK pool reward weight × BACK depositor weight

Interest returns/payment rules:

APY stands for annual percentage yield. For instance, token `M`’s deposit APY is 100%. Then user `A` deposits 100 `M`. One year later, the total interest return will be 100 `M` and the return will be automatically added into the deposit.