> For the complete documentation index, see [llms.txt](https://hummus-exchange.gitbook.io/hummus-exchange/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hummus-exchange.gitbook.io/hummus-exchange/concepts/withdrawal-fee.md).

# Withdrawal Fee

Withdrawal Arbitrage” is able to drain fund from the pool and is harmful to the protocol’s long term financial health. To counter the attacks, there is a custom withdrawal fees mechanism.

In most cases, however, a very small withdrawal fee is already sufficient to prevent such an attack.

Assume the withdrawal amount is equal to 1% of the pool:

| Cov Ratio | Withdrawal Fee |
| --------- | -------------- |
| >= 1      | -0.0000%       |
| 0.9       | -0.0011%       |
| 0.8       | -0.0093%       |
| 0.7       | -0.0518%       |
| 0.6       | -0.2731%       |

You can learn more about withdrawal arbitrage and the design on withdrawal fee [here](broken://pages/e58MGByRDAxk9wxHAU1w).