Section 6 Thunderloan - Lesson 39: Oracle Manipulation: Minimized - Some confusion in lesson video

[0xharryriddle]

I’m genuinely interested in this course. Thank you, Cyfrin, for creating it.

While learning lesson 39 in section 6 (Thunderloan), I found the order of actions in the flash loan activity confusing.

At 7:05 in the video, Mr. Collins mentioned that we could sell NFTs for plus 1 WETH and then undo the swap. However, i think we have to first undo the swap to put the price back to normal (1WETH = 10USDC) before selling the NFTs to take profit (1WETH).

[EngrPips]

Hello @thai-cong-nguyen, If I remember correctly, we are manipulating the price of USDC on a decentralized exchange that Whoops NFT marketplace is reading USDC price from to buy the NFT at a lower price. The point is the actual price of USDC across other true sources still remains valid even though we have manipulated the price on T-Swap exchange. So when we successfully buy the NFT on Whoops NFT marketplace, it doesn't matter if we undo the price we manipulated before selling our NFT or if we sell our NFT before undoing the price we manipulated as we will be selling our NFT to a platform that reads USDC price from a correct source. Please ask questions if this isn't clear enough.

[0xharryriddle]

Hi sir, thanks for your reply. I'm not sure if I understood correctly. I believe that we buy the NFT with 10 USDC after we manipulate the price, and then we will sell it for an additional 1 WETH once the price returns to normal.

[EngrPips]

We don't need to wait for the price to return to normal on the T-Swap dexes because manipulating the price of USDC On T-Swap will not manipulate the price of USDC on Binance, CoinBase, or Uniswap pool. We bought NFT for 10USDC, which is supposed to be equivalent to 1 WETH, but because we manipulated the price on T-Swap dex, we paid weth amount that is very small, and we can go ahead and sell the NFT on any other platform where it will be worth 1 WETH, so basically we used around 0.00001 WETH to buy the NFT on Whoops marketplace, and we went ahead to sell it for 1 WETH on some other platform like Opensea. Please don't hesitate to ask questions if anything is still confusing.

[0xharryriddle]

Oh, I was definitely clear. Thank you, sir.

[EngrPips]

Awesome, I am glad you figured it out. Keep crushing it, Friend.