Oracle Feed Types
A feed is one input inside an oracle route. It can be a market price, a contract conversion rate, an accounting value, or a DEX-derived price.
Feed type does not describe the whole oracle. It only describes what that feed leg means.
Market feed
A market feed reports a traded market price. This is the most common oracle use case: data providers usually aggregate prices from centralized exchanges, decentralized exchanges, or other market data sources.
Main tradeoff: market prices depend on market quality. Thin liquidity, venue concentration, stale markets, or stressed conditions can make the reported price easier to move or less representative.
Fundamental feed
A fundamental feed reports a protocol-defined conversion or accounting relationship, not a traded price. This is also called a reference, exchange-rate, or contract-rate feed. Chainlink calls this kind of custom feed an Exchange Rate Feed when it reads a conversion rate from an external onchain contract; Chainlink explicitly distinguishes those from market price feeds.
Common examples are LST share rates, ERC-4626 share-to-asset conversions, wrapper conversion rates, and other contract-defined exchange rates.
Main tradeoff: it can be less noisy than market pricing, but it adds contract and protocol risk. The feed may assume the conversion logic, reserves, redemption path, or wrapper behavior is correct and economically meaningful.
NAV feed
A NAV feed reports net asset value: an accounting value based on assets, liabilities, reserves, or collateralization. It answers a backing question, not a spot liquidity question.
Midas is a good example. Their docs define an mToken price as NAV: the total value of the underlying portfolio divided by the number of mTokens outstanding. Their oracle docs describe a NAV calculation and validation process, then pushing that NAV onchain to an oracle feed.
Main tradeoff: NAV usually does not mean executable onchain liquidity. It depends on the reporting source, valuation method, cadence, and operational process. Midas' own risk docs note that NAV can depend on third-party data sources and methodologies, may differ from prices on other venues, and may be delayed or estimated during volatile periods. NAV should not be read as a guaranteed redemption price unless the protocol explicitly guarantees that.
DEX feed
A DEX feed derives price from onchain DEX liquidity, such as a Pendle market or a TWAP-style pool price.
Main tradeoff: it is only as good as the pool or market it reads. TWAPs can lag because they average over time, and single-pool feeds can inherit that pool's liquidity, manipulation, and construction risks.
How to read a route
For any market, ask:
Does the full route correctly produce collateral / loan?Then check what each feed leg assumes: market liquidity, contract conversion, NAV reporting, or DEX pool pricing.