Borrow $1 million. Put up no collateral. Return it before the transaction ends. Welcome to flash loans 👻 But @aave started with something much more familiar: finding someone willing to lend you money. In 2017, Stani Kulechov launched ETHLend. It raised $16.2 million to connect lenders and borrowers on Ethereum. Smart contracts handled the loans. People still had to find a match. During the 2018–2019 bear market, the team rebuilt the system. Lenders would deposit into shared pools, and borrowers could borrow against collateral without waiting for someone to accept their request. Aave launched in 2020, with a feature that made the story much more interesting. A flash loan lets a smart contract borrow money without collateral, use it, and repay it with a fee—all in one transaction. For example: borrow funds, buy a token on one exchange, sell it for more on another, then repay the loan. If anything is left after fees and costs, that’s the profit. If the contract can’t repay, the whole transaction rolls back. You can still lose the gas fee, so a failed attempt isn’t free. That same mechanism can help users swap collateral or refinance debt. The loan exists only long enough to get the job done.