Last price, index price and mark price answer different questions

Three measurements

The last traded price records a recent execution on a venue. An index price combines selected market inputs according to a rule. A mark price is a valuation reference used by a particular trading system, often to determine unrealised profit or liquidation conditions. A platform may display all 3 while using only one for a given decision.

A brief trade at an extreme price does not necessarily move every reference equally. Conversely, stale or distorted index inputs can affect a mark even when a user is watching a different venue's chart. The formula, update interval and fallback behaviour are material parts of the system.

Reconstruct the decision

For a disputed liquidation, obtain the actual mark and index values, their input timestamps, the account state and the rule active at that moment. A screenshot of another exchange's candle cannot independently prove that a liquidation threshold was or was not reached.

Oracle freshness covers stale data. Liquidation mechanics covers the account calculation. The distinction is essential when analysing a platform incident: a bad reference price, insufficient collateral and poor execution can produce different losses even if they occur within the same second.

Sources et originaux

• Chainlink: price feeds
• Hyperliquid: liquidation mechanism