At 4:00pm Eastern the regular stock session ends. A stock perp does not notice. It keeps matching orders, charging funding and marking positions. The contract is the same one it was a minute earlier. What has changed is the market it follows, and that changes how every number on the perp should be read.
What keeps running
Trading continues around the clock, weekends included. Funding is still charged hourly. Positions are still valued at the mark, and a position can still be liquidated. None of the contract’s machinery pauses for the stock market’s hours.
What goes quiet
The perp follows an oracle, a reference price for the stock. During the regular session that reference reflects a share that is trading. After the close, the share trades thinly in extended hours and then stops. Over a weekend it does not trade at all. How a given book sources its reference in those hours is set by the team that listed it, and it is worth reading the market’s own specification.
What matters for the reader is simpler. Out of hours the mark is the price still being made. A gap between mark and oracle then is less a lean against a live market and more the perp moving while its reference waits. Mark versus oracle covers the two prices.
Three kinds of closed
Closed is not one state. On a weekday evening the stock is shut but index futures are trading, so the perp has a deep neighbor to agree or disagree with. On a weekend the futures are shut too, and the perp is the only live market on the name. On an early-close day the bell rings at 1:00pm and the quiet hours start sooner.
The weekend is the thinnest of the three. Fewer traders are present and fewer orders rest on the book. A move then is real, and it is also made by less money, which what a weekend move is worth takes up.
How the move is measured
The natural question out of hours is how far the perp has moved since the close. NoVo answers it by comparing the perp’s price now with the perp’s own price at the last regular cash close, taken from the 15-minute candle that ends at the bell. If the perp has no print at the bell, there is no figure. A number built on a stale anchor would look exact and mean nothing.
The result is a market price on another venue. It is what perp traders have done since the bell. The next cash session can begin somewhere else.
Where NoVo shows it
Trader shows this measure while the cash market is shut, for the index perps and the seven largest index names. It sends a push the first time an index perp is half a percent from its close. The implied open explains the index reading in full.