How Are Stock Perps Priced When the Stock Market Is Closed?

On a Saturday, a stock perp is not tracking the stock. The market is closed, so the price comes from the venue’s own order book, moved slowly and fenced in by bounds. When the market reopens, the venue switches back to the real price, and the gap lands on your position at once. Your weekend risk is the size of the fence, not the move you see.

Below is how four venues handle it. Parameters differ by market and change, so read the market’s spec page before you trade. This is general information, not financial advice.

Quick answer

A stock perp is a perpetual future on a stock’s price, settled in a stablecoin, with no share and no vote. In market hours it follows external feeds. After the close, most venues use an internal price from their own book, smoothed and capped inside bounds around the last external price. At the reopen it returns to the feed, which can jump. Funding and margin may change off-hours too.

Where does the price come from in market hours?

From an external oracle, combined with the venue’s own book into the mark price that drives your profit and loss, margin and liquidations.

Ondo Perps averages two oracles, Pyth and Stork, which also cover pre-market, post-market and overnight prices, five days a week.
Trade xyz uses a Relayer fed by a set of venues and data providers, and runs on Hyperliquid.
Arcus anchors the mark price to the oracle from 04:00 to 20:00 ET on US trading days.
Phoenix takes index prices from external market sessions.

What happens when the market closes?

The external feed stops moving: in Ondo’s words, the last price is broadcast on repeat with no real price discovery. So the venue builds its own:

Start from the last external price.
Measure the “impact price difference”: the gap between the average fill price for a set size and the current internal price.
Move the internal price toward that target slowly, with an exponential moving average.

The smoothing differs. Ondo and Phoenix smooth over an hour (Phoenix by default), Trade xyz over 30 minutes, and Arcus marks a 2.5-minute average of the book’s impact mid inside price bands. If buyers outnumber sellers all weekend, the price drifts up, but slowly and only within limits.

How wide is the fence?

On Ondo, Phoenix and Trade xyz the base bound is 1 divided by the market’s maximum multiple, measured from the last external price. A 20x market gets ±5%, a 10x market ±10%. In Ondo’s example, a 20x market that closes at $200 on Friday can trade between $190 and $210. Orders outside the bounds do not execute.

Two venues let the fence move:

Trade xyz re-anchors. When the oracle reaches 90% of the way to an edge, the window moves to that edge, up to a set number of times. In its own example a ±5% window at 20x can reach about +15.8% or -14.3% over a weekend.
Arcus widens. Bands are set from the market’s initial margin and can widen in steps (0.5x, 1x, 2x, 4x) after an hour of sustained pressure. At the 4x step, a 10x market can move up to ±40% from its anchor.

Trade xyz’s advice holds everywhere: manage risk “based on the maximum possible range,” not the one you see now.

Why does the price jump at the reopen?

The venue goes back to the live feed, which can be far from its weekend price.

Ondo Perps snaps back on the next update and clamps the mark price to about 50 basis points per update, so it steps to the new level.
Trade xyz reverts on the next tick, with Relayer updates clamped to ±50 bps.
Arcus seals a new anchor at each weekday close. “There is no weekend re-seal”: Friday’s anchor carries until the oracle takes over at 04:00 ET Monday.
Phoenix snaps the index price to the external price as soon as the feed returns.

A clamp spreads the jump over a few updates. It does not make it smaller.

Do funding and margin change off-hours?

On some venues. Arcus switches off-hours funding from the market-driven rate to SOFR + 0.5% (annualized), and opening or adding to a position needs more collateral, while maintenance margin stays the same. Ondo uses a 0.5x funding multiplier on equity perps at all times, which takes the baseline from about 11% a year to about 5.5%, and zeroes the premium on a weekend when the book is too thin. The basics are in What Is a Funding Rate on a Perp DEX?.

Can you be liquidated on a weekend?

Yes, within the fence. Ondo and Trade xyz both state that a position whose liquidation price sits outside the active bounds cannot be liquidated by price moves while those bounds hold. Bounds can move, though, and Arcus says its bands “do not prevent liquidation outright.” On Ondo, collateral held as tokenized stocks is still marked live, so it can move your margin while the perp price is bounded, and a weekend or holiday sale of collateral by its Auto-Exchange carries a closed-market settlement fee.

What this means for a farmer

Holding a stock perp over a weekend for volume or points means carrying the reopen gap. Size the margin against the widest range the venue allows, not Saturday’s bound. On a venue that raises initial margin off-hours, such as Arcus, a position opened before the close needs less collateral than the same one opened on the weekend.

Checks before you hold over a weekend

When does the venue switch to internal pricing, and back?
What is the bound for this market, and can it re-anchor or widen?
Where is your liquidation price against the widest possible range?
Do funding and initial margin change off-hours?
Are there extra fees on closed-market liquidations or collateral sales?

Frequently asked

Are dividends paid on stock perps? Rules differ. Arcus reflects dividends and splits in the oracle price instead of paying them through funding.

What is the reopen gap? The jump when the venue switches from its weekend price back to the live external price.

Can the weekend price go anywhere? No. Each venue caps it around the last external price, though Trade xyz and Arcus let the cap move.