_Follow along with the video lesson:_ --- ### Exploit - Oracle Manipulation - Introduction Alright, we're cookin' now! Next question! ```js // @Audit-Question: How is the fee being calculated? function getCalculatedFee(IERC20 token, uint256 amount) public view returns (uint256 fee) {...} ``` We'd identified an issue in this function previously, in that we're for some reason calculating a fee in weth - but besides this vulnerability, is there anything else regarding fee calculation that is potentially exploitable? Hint: ```js uint256 valueOfBorrowedToken = (amount * getPriceInWeth(address(token))) / s_feePrecision; ``` Spotting this issue comes with a little bit of experience. I can tell you it's related to utilizing a Dex as a price oracle. Ask yourselves: **_What would happen if the price of an asset on TSwap could be manipulated? What would the impact on Thunder Loan be?_** In 2023, `Price Oracle Manipulation` was the #1 attack vector in DeFi resulting in over `$198,000,000` in lost or stolen funds. In the next lesson we'll be introduced to what oracle manipulation is, how it works and what can be done to protect against it. See you there.