I've noticed that many people in DeFi talk about flash loans without really understanding how they work. Personally, I found it fascinating at first, but also a bit scary once I understood the risks.

So here it is, a flash loan is essentially an unsecured loan that you can borrow without putting up collateral. The crazy part? Everything must be repaid within the same transaction. If you don't repay, the transaction is canceled as if nothing happened. It's powerful because it enables arbitrage, refinancing, liquidations... but that's also where it becomes interesting and dangerous.

The problem is, some have figured out how to exploit flash loans. The attacker borrows a large sum, uses it to manipulate prices on a DEX, then on another platform takes advantage of the distorted price to withdraw assets. And boom, they repay the loan with the profit. All in a single transaction.

There have been some significant cases. bZx in 2020 lost $1 million due to price manipulation. Harvest Finance? $34 million disappeared in minutes. And PancakeBunny with $45 million in losses when the prices of BUNNY and USDT were manipulated in the pool. It shows how destructive a flash loan exploit can be.

Why is this possible? Oracles are not protected enough, there are flaws in smart contract logic, and often there’s no serious verification against price manipulation.

The thing is, protocols can defend themselves. Use reliable oracles like Chainlink, implement delays with time-weighted average prices, properly verify input data. And regular audits are not a luxury.

For us as users, it’s simple: avoid large sums in unaudited protocols. I check the news regularly to see if a protocol has been hacked. And honestly, I prefer sticking to proven DeFi solutions.

Flash loans are a truly innovative technology with huge potential. But like any powerful tool, they can be used to cause damage. Understanding how they work and being cautious in your choices is key to avoiding getting caught out.