# FAQs

## **Q1. Please introduce the loan interest rate, and how to calculate it.**

Loans can be repaid anytime and there is no fixed term for a decentralized lending protocol.

The interest rate on Roolend fluctuates based on supply and demand. The higher the fund utilization rate, the higher the interest rate, and vice versa. Therefore, Roolend's borrowing interest rate/ supply interest rate refers to the rate of each block.

## **Q2. Why is the actual APY lower than the displayed one?**

APY is the annual percentage yield. For example, if the supply APY of M token is 100%, it means that if a user deposits 100 M tokens, the total yield in one year is 100 M tokens.

The interest of the decentralized lending protocol is calculated and distributed according to the compound interest of the block. The daily income cannot be calculated as APY/365. The longer the deposit time, the higher the compound interest curve and the return.

## **Q3.  Why are reward amounts different among the same amount of different tokens?**

APYs of different pools are based on the total amount of borrowings and supplies of the pools. Rewards are distributed based on different APYs.

## **Q4. Why is there no response when I deposit or borrow assets?**&#x20;

In general, there may be 2 reasons:

1\. The wallet node is down. Please check whether the wallet node is normal in the setting;

2\. The chain is congested. Your last interaction is congested on the chain, which causes your actions afterwards cannot be performed. If you are using the Metamask wallet, you can check it under the “Activity”. If there is an on-chain operation in the queue, please choose "accelerate" or "cancel". You can perform other operations after it gets back to normal.

## **Q5. Why is there still a small amount of loan after all borrowed assets have been repaid?**

There is interest of borrowing, which will be calculated in the repayable loan. If you borrow assets, the borrowed assets < repayable assets. During the time when the repayment is waiting for the transaction package, new loan interest happens to be generated. This part of the newly generated interest is not included in the original principal and interest. You can try to repay the loan again, and usually it can be paid off after 1-2 times.&#x20;

## **Q6. Why does the value of mortgage assets suddenly decrease?**

It will trigger liquidation when your loan utilisation rate reaches 100%. The liquidator will obtain the mortgage assets of the liquidated user, and receive a 5% reward, while the liquidated user will be fined 5%.

Please pay close attention to loan utilization rate to avoid triggering liquidation.

## **Q7. Does Roolend charge any fee？**

Roolend only charges 0.25% handling fee for borrowing assets. There is no handling fee for deposits and withdrawals.

## **Q8. If I mortgage BTC and borrow USDT, what token should I repay ?**

The basic principle is what to borrow, what to repay. In this case, you should repay USDT.

## **Q9.Have your contracts been audited?**

Yes, our smart contracts have been audited by FairyProof.

## **Q10. What do the two figures below deposit income/borrowing cost of a single token mean?**

The former is the annual deposit interest rate/the annual interest rate of borrowing, and the income/cost refers to token deposit/borrowing; the latter is the mining yield rate, and the income is ROO token. For example, if a user deposits USDT, among the 6.42% of the deposit income, 4.18% is the USDT yield, and 2.23% is the ROO income of taking. 6.42%=4.18%+2.23%. In the same way, if one borrows USDC, the borrowing cost is 6.31%. 10.41% is USDC interest, 4.10% is the ROO yield of mining, and 6.31%=10.41%-4.10%<br>
