The volatility of DeFi asset prices, particularly in illiquid markets, underscores the importance of using aggregated price data that resists manipulation when building smart contracts. Index funds, which track groups of assets, offer a straightforward and cost-effective method for consumers to achieve diversified exposure in both traditional and DeFi markets. However, the reliability of these indices hinges on accurate and tamper-proof pricing data, as any manipulation could undermine their purpose and stability. Chainlink addresses this challenge by providing decentralized, pre-aggregated price oracles that ensure the integrity and security of index prices across a broad spectrum of financial products. These oracles enable developers to build more secure DeFi applications by offering tamper-proof access to index price feeds, thus meeting the growing demand for robust financial products in the DeFi space.