How Blockchain Oracles Work and Where DeFi Trust Moved

A smart contract can work out a loan, a liquidation or a swap to the last decimal place. What it cannot do is find out what anything is worth.That limitation sits beneath every lending app and exchange in decentralised finance (DeFi), and it leads to a question that is easy to skip past: when a lending protocol says the assets you pledged as collateral are worth a certain amount, who told the contract, and why should it believe them?The answer is an oracle: a service that carries information fro