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To make all that work, the smart contract must monitor the price of bitcoin using a third-party source of data called an “oracle.” Oracles allow smart contracts to get external information needed for transactions. Right now oracles are mainly used to stream crypto prices, but they could provide information on almost anything, from stock prices to weather data to election results.
A number of oracle networks aggregate data from multiple sources and provide it to DeFi projects. The biggest is Chainlink, whose creators say it supports over $80 billion worth of assets tied up in various smart contracts. Its data sources include the Associated Press, which agreed in October to provide data on the economy, sports and elections through Chainlink.
Pyth is undercutting rivals with free data—unlike Chainlink, for instance, whose oracles cost money to use.
From Why the World’s Biggest Traders Are Betting on Blockchain Data – WSJ:
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