The news lands at 9pm. The exchange is shut.
A perpetual on a share does not observe the closing bell. That is the whole appeal and it comes with conditions that are worth knowing before you rely on it.
What Arcus is- Type
- Perpetuals on stocks, gold, crypto and indices, one book
- Markets
- 60+ listed, read live from the venue
- Hours
- 24/7, including when the underlying share is closed
- Our data
- 4M+ order-book snapshots at a 5.5-second cadence
Why it can trade at all
A perpetual settles against a price feed, not against the stock exchange. As long as the venue has a reference price and two willing sides, the book can match. Nothing has to be delivered and no clearing house has to be open.
At the moment of writing, thirty-six of the fifty-eight markets on Arcus were outside regular trading hours and still quoting. That is not a special mode: it is the ordinary state of the venue for most of the week, because the stock exchange is open for roughly a third of it.
- Settlement is against a price feed, so no exchange needs to be open.
- 36 of 58 markets were outside regular hours at the time of writing, and trading.
- The stock exchange is open about a third of the week. The perp is open all of it.
What changes when the exchange closes
Three things, and all three are measurable rather than theoretical. The book thins out, because most participants trade during the day. The spread widens as a direct consequence. And the venue usually raises the margin requirement, because a thin book gaps more easily.
The reference price also updates less often, which matters more than it sounds. Between updates the contract is driven by the order book alone, so it can move away from where the share will open and come back when the feed catches up.
- Thinner book, wider spread, higher margin: all three, together.
- The reference price updates less often, so the book leads more than usual.
- Size that fills instantly at midday can take a while at midnight.
The gap that is not a gap
On a traditional share, news at 9pm shows up as a gap at the next open: the price jumps from where it closed to where it should be, and nobody could trade in between. On a perpetual the same news is priced immediately, in a thin book, by whoever is awake.
That is genuinely useful and it is not free. The price discovered overnight by a handful of participants is less reliable than the price discovered at midday by everyone, and it can overshoot. If you are trading the reaction, size for the possibility that the overnight move is half-retraced by the open.
- News is priced when it lands, not at the next open.
- Overnight discovery is thin discovery: it overshoots more often.
- Size for a partial retrace, not for the overnight print being right.
Questions
Can you really trade stocks on weekends?
On perpetual markets, yes. The contract settles against a price feed rather than through the stock exchange, so the book stays open. What changes is depth: fewer participants means wider spreads and usually a higher margin requirement.
What happens to a stock perpetual when the exchange is closed?
It keeps trading, driven mainly by the order book because the reference price updates less often. The spread widens and margin requirements typically rise. Positions are not closed or paused at any point.
Is the overnight price accurate?
It is a real price in the sense that you can trade at it, and a less reliable one in the sense that fewer participants set it. Overnight moves overshoot more often than daytime moves and are frequently partly retraced when regular hours resume.
Does funding still accrue overnight and at weekends?
Yes. Funding is charged on the venue's own schedule regardless of whether the underlying market is open, so a position held over a weekend pays or collects for that whole period.