Capped Oracles are a type of price oracle designed to limit the maximum value (or growth) of an asset’s reported price to protect against manipulation or sudden volatility.
Capped Oracles set an upper bound (a “cap”) on the price that can be reported for an asset in the protocol. This mechanism helps mitigate the risk of price manipulation—especially for low-liquidity or volatile assets—which could otherwise allow users to borrow excessively or liquidate positions unfairly. By capping the price, the protocol ensures that users can’t exploit sudden, artificial price spikes to increase their borrowing power or trigger liquidations.
Venus Correlated token oracles calculate the USD price of assets strongly correlated with other assets, for example wstETH and stETH, taking into account the onchain exchange rate between the correlated assets. Specifically, Capped Oracles limit the considered growth of that exchange rate on correlated assets.
Cached Prices is a new feature integrated on the Venus oracle contracts, that reduces the gas consumed by the functions that collect and return the prices, using Transient Storage to cache the prices in the smart contract memory. This drastically reduces the needed gas when the price for one asset is requested more than one time in the same transaction (common behaviour during liquidations or complex transactions).
The deployment and configuration of the Capped Oracles and Cached Prices will be performed on several phases. It requires the upgrade of the base contracts (ResilientOracle, BoundValidator, ChainlinkOracle, BinanceOracle and RedStoneOracle).
VIP execution simulation: in a simulation environment, validating the new implementations are properly set on opBNB, and the asset prices doesn’t change
Deployment on testnet: the same upgrade has been performed on opBNB testnet, and used in the Venus Protocol testnet deployment
Chaos Labs supports and encourages the use of Venus Capped Oracles in all the markets which include yield bearing collateral, to prevent price manipulation of the exchange rate. In light of the upcoming adoption of Capped Oracle in the Base instance, we cover the parameters for the wsuperOETHb asset in the following recommendation.
Capped Oracle Parameters
Historical yield data for wsuperOETHb show that exchange-rate growth becomes statistically smooth once returns are measured over a 7-day horizon. This behaviour stems from Origin’s dripper contract, which streams the underlying OETH yield at a near-constant rate, suppressing short-term variance in the observed APY. To translate this evidence into a conservative growth ceiling for the Capped Oracle, Chaos Labs selects the highest annualised return recorded within the last 180 days when yields are smoothed over that 7-day window and then adds the standard deviation of the 1-day yield series to accommodate transient rate spikes.
The outcome of this calculation is an Annual Growth Rate of 14.26 %.
A snapshot interval of 30 days allows the reference exchange rate to be refreshed monthly, limiting cumulative deviation from the true on-chain rate.
Finally, to prevent the oracle from capping legitimate growth in the weeks immediately following market launch, the initial snapshot gap is sized to equal one month of yield at the recommended annual growth rate, corresponding to 1.11 %.
As such, for the asset of wsuperOETHb on the Venus Base instance, we recommend the following Capped Oracle Parameters:
Parameter
Value
Annual Growth Rate
14.26%
Snapshot Interval
30d
Snapshot Gap
1.11%
Disclaimer
Chaos Labs has not been compensated by any third party for publishing this recommendation.
