I'm looking to develop a smart contract which uses real-world, market data.

I was looking through Chainlink documentation and understand that as of now, there's no support for a decentralized oracle concerning public market data (stock prices). I understand the reasoning behind having a decentralized oracle: the risk of single node failure. However, would it really be risky to use data from a few highly reliable sources (Yahoo finance, Google finance, Nasdaq) for smart contract functionality? Is this even possible?

Where exactly can I learn about using centralized sources of data such as YF / Google / Nasdaq in my smart contract? Or is this strictly prohibited?

1 Answer 1


You could use Tellor to grab the prices for stocks. It's more of a general purpose oracle that's live versus just some feeds.

I think the big issue here is that you'd want to be specific as to what you wanted. There's a difference between the price of AAPL, the price of AAPL according to this API, and the closing price of AAPL on a given date. Each have drawbacks and advantages and obviously the more centralized of a source you have, the greater of a risk you run for censorship. I wrote a more nuanced article on it here: https://medium.com/tellor/subjectivity-in-oracles-f7c3c06f69f1 if you're curious.

  • Excuse my ignorance, but I couldn't seem to figure out how to find stock prices, rather I found common cryptocurrency-fiat conversions. If you could elaborate on how to use this oracle, that'd be great. Additionally, if I wanted full customizability of stock quotes, I could create my own Decentralized Oracle Network, right? Is this process worth it and if so, how would I go about doing it. Commented Feb 3, 2022 at 18:23
  • Sorry, yeah it would be the same as creating a new crypto-fiat price feed. the whole "network" thing is a link problem. You just have to make a new queryID that is the stock price. So for instance your new ID could be the AAPL/USD price, and you would just add it to the catalog (make a PR here: github.com/tellor-io/dataSpecs/blob/main/catalog.md). so that the reporters know what you want.
    – thefett
    Commented Feb 4, 2022 at 14:59

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