NIFTY monthly expiry — 25 August 2026

The last session of a NIFTY monthly option contract, and the longest-held of the index's expiries. A monthly series has been listed for months, so it carries positioning that accumulated over that whole span rather than over a week — the open interest unwinding is older and larger.

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

The same decay a weekly carries, over a bigger book. Because a monthly series is also the one most hedging and most rolled positions sit in, the unwind is spread across the last days rather than the last hour, and the futures roll into the next month runs alongside it. The desk measures the index's move on the day itself; the roll is visible in the futures build-up on the option chain page.

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.

going into the last 220 of these, the option market was asking about 0.7% by expiry and the market travelled about 0.6% — the move was the larger of the two about 35 times in 100.

half of them landed between 0.29% and 1.14% either way