Monthly Expiry — Rollover, Settlement and the Stock-Delivery Trap
The last Tuesday combines index and stock F&O expiry. How rollover works, why stock options settle in shares, and what to do before the close.
The last Tuesday of the month is the heaviest expiry in the NSE calendar: NIFTY and BANK NIFTY monthlies, plus every single-stock derivative, all settle together. It's also where the most expensive beginner mistakes happen — because stock F&O settle differently from index options.
This chapter covers the three things that matter on a monthly expiry: rollover, the cash-vs-physical settlement split, and the delivery obligation that can turn a forgotten position into a six-figure surprise.
Rollover — moving a position to next month
A position you want to keep past expiry must be rolled: close the expiring contract and reopen it in the next month's series. Traders do this in the days before expiry, and the aggregate behaviour is tracked as the rollover percentage — what fraction of open interest moved to the next series rather than being closed out.
High rollover (positions carried forward) signals conviction that the trade has further to run; low rollover (positions closed, not carried) signals traders booking out. It's a sentiment read in its own right, especially for single stocks.
Cash vs physical settlement — the critical split
Index options and futures (NIFTY, BANK NIFTY, SENSEX) are cash-settled — settled to the index value, no delivery.
Single-stock futures and options are physically settled. If you hold an in-the-money stock option or a stock future to expiry, you are obligated to take or give delivery of the actual shares — and the cash value of that delivery can be many times the option premium or margin you put up.
This is the trap: a ₹3,000 long call on a ₹2,000 stock, if it expires in-the-money and you forget to square it off, can leave you obligated to buy the full lot of shares — lakhs of rupees — plus delivery margins the exchange starts levying in expiry week.
What to do before the close
Index positions: decide to settle in cash (do nothing, let it expire) or close early to lock the price. No delivery risk either way.
Stock positions: unless you specifically intend to take/make delivery and have the cash or shares, square off or roll before expiry. Brokers raise margins on stock F&O through expiry week precisely to flush out positions that would otherwise trigger delivery, and some auto-square-off ITM stock options near the close — but never rely on that; manage it yourself.
Common misreads
- Thinking all F&O is cash-settled. Index is; single stocks are physically settled.
- Assuming the broker will always auto-square-off your ITM stock option. Some do, some don't — never rely on it.
- Ignoring the higher delivery margins brokers levy on stock F&O during expiry week.
Key takeaways
- Monthly expiry is the last Tuesday (NSE): NIFTY, BANK NIFTY and all stock F&O settle together.
- Rollover = closing the expiring contract and reopening next month; rollover % is a sentiment gauge.
- Index F&O = cash-settled. Single-stock F&O = PHYSICALLY settled (actual share delivery).
- An ITM stock option held to expiry creates a full-value delivery obligation — far bigger than the premium.
- Square off or roll stock positions before expiry unless you intend delivery and have the cash/shares.
Monthly expiry — settlement and rollover
What's the difference between cash and physical settlement at expiry?
Cash settlement (all index products — NIFTY, BANK NIFTY, SENSEX) pays the difference in cash to the index value; nothing is delivered. Physical settlement (all single-stock futures and options) means actual shares change hands — if you hold an in-the-money stock derivative to expiry, you must take or give delivery of the underlying shares.
I forgot to close an in-the-money stock option — what happens?
It goes to physical settlement: you become obligated to buy (for a call) or sell (for a put) the full lot of shares at the strike. The cash involved can be many times your premium. Brokers raise margins through expiry week and some auto-square-off ITM stock options, but you should never depend on that — manage the position yourself.
What does rollover percentage tell me?
It measures how much open interest moved to the next month's contract rather than being closed at expiry. High rollover means traders are carrying positions forward (conviction the move continues); low rollover means they're booking out. For single stocks it's a useful sentiment signal alongside price and OI buildup.
When exactly is monthly expiry now?
The last Tuesday of the month for NSE products (NIFTY, BANK NIFTY, single stocks). SENSEX on the BSE is the last Thursday. If the day is a holiday, expiry shifts to the previous trading session.
Do I need to roll, or can I just let positions expire?
If you want to keep a view past expiry, you roll (close the expiring contract, open the next month). If you're done with the trade, let index positions cash-settle or close them — but close or roll stock positions to avoid an unwanted delivery. Letting a position 'just expire' is only safe for cash-settled index contracts.