# Asset Valuations and Oracles **Stack has been designed to make borrowing better/safer for users, less predatory and somewhat less risky (leverage always risky!)** Most collateral tokens have a standard oracle with a volume weighted/time-weighted average price. The current market price of the collateral tokens is always shown in the UI, however the oracle value is used to calculate position parameters including LTV. In most cases the oracle price is a representation of the market price history. {% hint style="warning" %} LTV calculations use the oracle price which in the case of $USTB and $MORE are not always derived from the market price. {% endhint %} The exception to this rule is `$USTB`, which has a steady oracle price that always returns $1. We take on the risk, that `$USTB` will always be redeemable for $1.00 so users can't be liquidated if `$USTB` depegs. If `$USTB` is trading at $0.90, Stack still values it as $1.00. Additionally, the default oracle for `$MORE` fixes the price of `$MORE` at $1.00. Our goal is to avoid a situation were `$MORE` trading above a dollar opens up a position to liquidation. Even if price manipulations push `$MORE` up, your position is safe. **Example:** A users has an open position where the borrowed amount is very close to the max LTV. If `$MORE` goes above a dollar, the borrowed amount may technically move above what's allowed. In this case, the `$MORE` price cap at $1 prevents the liquidation. ## Oracles
VaultOracleAddressNotes
USTBCollateral token oracleLinkStatic, always returns $1
USTBBorrow token oracleLinkStatic, always returns $1
arcUSDCollateral token oracle
Oracle wrapper		Link
Link		Maintained by team, notes below
arcUSDBorrow token oracleLinkStatic, always returns $1
PTaCollateral token oracle
Oracle wrapper		Link
Link		Maintained by the team (same as arcUSD)
PTaBorrow token oracleLinkStatic, always returns $1
reETHCollateral token oracleLinkMaintained by DIA
reETHBorrow token oracleLinkStatic, always returns $1
Static oracles are hard-coded values into the vault and can only be updated via multi-sig. These values can not expire nor go stale, so they're not updated on a regular basis. The arcUSD oracle is maintained by the Arcana team as there is currently no safe, decentralized solution to reliably manage this process, where 3rd party data failures would not trigger false liquidations. The oracle confirms the arcUSD backing value to Stack every 23.5 hours. In the event arcUSD were to become under-collateralized, the Arcana team is automatically notified and the new value will be confirmed by the team, updating the oracle through a 2-of-3 multisig transaction. Any subsequent change in backing value would also require multisig approval. DIA oracles are completely maintained by DIA, fully independent from the Stack team using the default values of 0.5% price movement to trigger an update and a 24-hour heartbeat. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.stackmore.xyz/using-stack/asset-valuations-and-oracles.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.