What is the mark price?
The mark price is Orderly Network's estimate of what a perpetual contract is worth. SilkDEX uses it — not the last traded price — to compute unrealized profit and loss and to decide liquidations, so a single trade in a thin order book can't liquidate you. It combines the index price, the funding rate and the order book.
Three prices you'll see
| Price | What it is |
|---|---|
| Index price | A fair spot price for the underlying asset, from several sources |
| Mark price | The median of three estimates (below); used for PnL and liquidations |
| Last price | The most recent trade on Orderly's order book |
How the mark price is calculated
mark price = median(P1, P2, futures price) P1 = index × (1 + last funding rate × time to next funding / interval) P2 = index + 15-minute moving average of the basis futures price = median(best bid, best ask, last price)
Orderly then caps how far the mark price may sit from the index.
How the index price is built
Crypto: a volume-weighted average of major spot exchanges, reweighted every 5 minutes on the previous 4 hours' volume; a source more than 5% from the median is capped and a source silent for over 10 seconds is dropped. Stocks, indices, commodities and FX: Orderly-listed markets use named feeds (Pyth and Chainlink for NVDA, TSLA and GOOGL, for example); community-listed markets use the sources their lister chose.
Outside market hours
For stock, commodity and FX perps the index freezes while the underlying market is closed, and Orderly lets the mark price move further from it (about 1–1.5% instead of 0.2–0.3%). See trading hours.
FAQ
Why does SilkDEX liquidate on the mark price instead of the last price?
Because one trade in a thin order book can move the last price. The mark price blends the index from several venues with the funding rate, so liquidations follow the real market rather than a single fill.
Why doesn't the index price move on weekends for stock perps?
Because the US stock market is closed: the index stays at its last value until the market reopens. You can still trade, but liquidity is thinner and the price can gap at the open.
Related: What is a funding rate? · What is liquidation on SilkDEX? · When do stock and gold perps trade? · All terms
Source: Orderly: Mark price, index price and last price. SilkDEX figures from Orderly's public API as of 2026-10-13.