Skip to main content
Index price is the network’s answer to what is this asset worth right now on the wider market. It is an input, not an execution price: nothing fills at the index. It anchors mark price, it sets the reference for funding, and through both it determines whether positions survive. That makes it the most consequential external input the system takes. Everything below exists because a price that can be pushed is a liquidation engine that can be aimed.

​
Why the venue builds its own

The alternative is to consume someone else’s oracle, and the failure mode of that arrangement is well documented: a venue that references a price influenced by its own market creates a loop where a distortion in one place becomes a forced liquidation cascade in another. Building it in-house means the sources, weights, and thresholds are all inspectable and tunable, and none of them point back at this venue’s own book.

​
From venue quotes to one number

Normalize and convert the quote currency
Clamp every source to the median ± a band
Weight by volume, spread and stability
Cap the weight any one venue can carry
Index price
So the median that follows is taken over comparable numbers
Major crypto 1% · stablecoins 0.5% · everything else 3%
Stability compares recent volume against a longer run, so a sudden burst on one venue cannot buy influence
However good its quotes look
An input, not an execution price — nothing fills at the index
Exchange feeds in, one number out
What the step removes
Clamping rather than discarding: discarding lets an attacker shrink the sample by pushing one venue away, which raises the weight of everything left.
Each step removes a different way the result could be pushed. Normalize. Feeds arrive on their own schemas and quote currencies. Prices quoted against a currency other than the settlement currency are converted before anything else happens, so the median that follows is taken over comparable numbers. Clamp outliers. A median is computed across all sources, then every source is pulled to within a band around it. The band is tightest where markets are deepest. The choice to clamp rather than discard is deliberate. Discarding an outlier lets an attacker shrink the sample by pushing one venue away, which increases the weight of everything remaining. Clamping keeps every source counted while bounding how far any one can pull. Weight by quality. Sources are combined by weighted mean rather than equally, on three factors:
  • Volume — a venue with more real turnover carries more information
  • Spread — a tighter book is a more confident quote
  • Stability — recent volume compared against a longer-run average, so a sudden burst on one venue does not buy influence
Cap per venue. Even a source scoring well on all three is capped, so no venue can dominate regardless of how good its quotes look. The combined effect is a cost floor on manipulation: moving the index meaningfully requires moving several independent venues at once, at their real depth, and holding it.

​
When a source misbehaves

Three defenses run continuously, each addressing a different failure. When a source’s weight goes to zero, the remaining weights scale up proportionally. The index does not gap because one venue disconnected.
A crossed book — bid at or above ask — is not a tradable market, it is a broken feed. Accepting it would let a malfunctioning venue inject an arbitrary mid into the aggregate.

​
Update cadence and staleness

The index recomputes roughly every three seconds and is certified inside consensus, so the price a transaction settles against was signed by the same validator quorum that committed the transaction. See Oracle for how that certification works. Freshness is checked before a validator will sign: a stale reading produces no submission rather than an old one. Downstream, mark price treats an index older than about ten seconds as unavailable for that block and proceeds without it.

​
Index price is not mark price

Keeping them separate is what lets the mark reflect local conditions — a real premium or discount on this venue — without letting local conditions become the only thing it reflects.
These mechanisms bound how far a single source can move the index. They do not make the index correct. In a market-wide dislocation, or a coordinated move across several major venues, the index moves with the market — because at that point it is not being manipulated, it is reporting. See Risk disclosures.

​
Where to go next

Mark price

How the index becomes the number that governs your position.

Funding

How the gap between mark and index is priced and settled.

Oracle

Certification in consensus, and why price availability gates block production.

Risk disclosures

What price risk remains, and what it can cost.