wstETH

wstETH is the non-rebasing wrapped form of Lido's staked ETH (stETH).

wstETH is the non-rebasing wrapped form of Lido's staked ETH (stETH). It is priced purely from its on-chain redemption rate — no market oracle sits in the pricing path. This ICustomPriceFeed adapter reads Lido's wrap rate and scales it by the NAV's own ETH/USD. Any market divergence (e.g. a stETH depeg) is surfaced by a market monitor feed, not by moving this price.

Source: wstETH_CustomPriceFeed.sol

Mainnet feed. The L2 deployments use a different oracle composition — see wstETH (L2).

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Approach

stEthPerToken() × ETH/USD — the wrap rate gives ETH per wstETH (treating stETH/ETH ≡ 1.0, Lido's fundamental redemption invariant), then ETH/USD converts to USD. This is a pure-fundamental BaseCustomPriceFeed subclass: it implements only the _rate() hook and carries no market stETH/ETH leg. The ETH/USD term is not a hardcoded oracle — it is the NAV's own price for WETH (via getPriceDataNoDivergence(WETH)).

wstETH (Mainnet) price feed — the on-chain wrap rate scaled by the NAV's ETH/USD, with the staleness gate.

The ETH/USD term is sourced from the NAV's own primary feed — see Base/USD from the NAV's own selector.

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Price calculation

price = stEthPerToken (18) × (ETH/USD, NAV-selected) (8) / 1e18      // USD, 8 dec

Input	Source	Description
stEthPerToken	IwstETH.stEthPerToken() on wstETH (18 dec)	stETH per 1 wstETH (the wrap rate)
ETH/USD	NAV — getPriceDataNoDivergence(WETH) (8 dec)	the NAV's primary WETH/USD price

The wrap rate stEthPerToken increases monotonically as Lido staking rewards accrue. Pricing off stEthPerToken alone assumes 1 stETH is redeemable ~1:1 for ETH; a real stETH depeg does not move this price but instead trips the divergence monitor (below). Output decimals are inherited from the ETH/USD feed (8).

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Constructor

constructor(
    address wstEth_,
    address nav_,
    address baseAsset_
)

Parameter	Description
wstEth_	wstETH token address (also the supported underlying)
nav_	NAVCalculator (proxy) — supplies the base asset's USD price via getPriceDataNoDivergence
baseAsset_	the registered base asset whose USD price is read (WETH)

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Staleness

getLatestPrice() returns stale if stEthPerToken() returns 0, or if the NAV reports the base asset (WETH) primary feed stale. There is no market-leg heartbeat — the wrap-rate call has no independent heartbeat, and the only external timestamp is the NAV's selected WETH feed, which supplies the reported updatedAt.

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Divergence monitors

wstETH carries a divergence tolerance of 250 bps and is watched by two market monitor feeds — a Redstone and a Chainlink wstETH/USD feed. On each NAV read the primary is compared against them; if the worst-case deviation exceeds 250 bps the asset is flagged irregular (a signal, not a price change). See Primary feed and divergence monitors.

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Chains

Deployed on Ethereum. For the rollup deployments using a direct Chainlink wstETH/ETH feed, see wstETH (L2).