Mark price vs last price
Two prices on one screen. Only one can liquidate you.
Two prices. One can liquidate you. Last price is the most recent trade on the book. Mark price is a fair price built from the real market. They are usually close. Usually.
Last: whatever just traded. One wild order in a thin book moves it instantly. It is honest, and it is twitchy.
Mark: smoothed and fair. Built from the oracle and the book, it ignores a single bad print. Hyperliquid uses it for liquidation and P&L. So does MemeSim.
Liquidation, TP and SL all watch the mark. A trade 3% below the market for one second cannot liquidate you. A real move can.
If the two prices split, slow down. A wide gap means a thin or panicked book. Your fills happen on the book, not at the mark. Use a limit order.
Which price?
One wild print.
The scary print. Long ETH at 5x, $100 margin. Last price just flashed 3% lower for a second; the mark barely moved. Buy means add, skip means hold, sell means panic close.
Mark price vs last price · 3 min
Two prices. One can liquidate you.
Last price is the most recent trade on the book. Mark price is a fair price built from the real market. They are usually close. Usually.
Go deeper
Last price is the most recent fill on the order book, so one large order in a thin moment can move it several percent for a second. Mark price is Hyperliquid's fair price, built from the oracle and the book, and it is what MemeSim uses for liquidation, unrealized P&L and TP/SL triggers. Your own fills still happen on the book, so when the two prices split, a limit order protects you from a bad fill.