NIFTY weekly expiry — 22 September 2026

The last session of a NIFTY weekly option contract. Weekly contracts are listed with a short life, so a series reaches its expiry with far less open interest behind it than a monthly one — the positions in it were mostly opened in the same week and are closed in the same week.

Who decides

The exchange decides it, not the market. NSE publishes the contract calendar well in advance, so the date is known months ahead, and it computes the settlement value from NIFTY's own closing calculation at the end of the session. Every contract in the series is cash settled against that one number: nothing is delivered and no position carries into the next day.

What moves

Time value is what goes. An option at a strike near the close carries almost none of it by the last hour, so premium at the money decays to its intrinsic value over the session while strikes further out go to nothing. Open interest at those strikes is closed out or rolled into the next series, which is why the chain's own open-interest picture is least readable on this day and most readable on the one after.

What it is not

The expiry is not an announcement. Nothing is published on the day and no new information about the economy arrives with it — what changes is that one set of contracts stops existing and the positions held in them have to be closed, rolled or settled. So the figures below are a record of what NIFTY did on these sessions, not a claim that the expiry caused any of it, and they carry their own count so a reader can see how much they rest on.

the option market is asking about 0.8% by the 22 Sep expiry, 4 days away.

going into the last 308 of these, the option market was asking about 0.7% by expiry and the market travelled about 0.5% — the move was the larger of the two about 38 times in 100.

half of them landed between 0.25% and 0.90% either way