Listen closely, dear trader — expiry is the moment an option contract ceases to exist and every open position must be settled, either by cash or by delivery of the underlying. In the Indian F&O segment this happens on a fixed calendar day for each index, and missing the nuance can turn a winning trade into a costly lesson. I have seen many retail participants chase the last‑minute premium only to watch it evaporate at the closing bell.
Disclaimer: The views expressed here are for educational purposes only and do not constitute investment advice. Always consult a SEBI‑registered advisor and use tools like the NSE F&O margin calculator before sizing any position.
What Is Option Expiry in the Indian Market?
Expiry is the predetermined date when an option contract expires worthless if it is out‑of‑the‑money (OTM) or is automatically exercised if it is in‑the‑money (ITM). On the National Stock Exchange (NSE) all index options are European‑style, meaning they can be exercised only on the expiry day itself. This single‑day settlement window creates a unique volatility spike that seasoned desk traders anticipate weeks in advance.
Weekly vs Monthly Contracts — The Real Dalal Street Mechanics
Nifty and Bank Nifty offer weekly expiries every Thursday, while Sensex and FinNifty follow a Friday weekly cycle; monthly contracts for all indices expire on the last Thursday of the calendar month (or the previous trading day if Thursday is a holiday). Weekly contracts give you tighter gamma exposure and lower premium decay, but they also demand sharper timing — something the Black‑Scholes Greeks calculator can help you visualise. Monthly contracts, on the other hand, carry higher time value and are favoured by institutional writers who sell premium over a longer horizon.
Expiry Day Schedule by Index (Verified Against Latest NSE Circulars)
| Index | Weekly Expiry Day | Monthly Expiry Day | Settlement Type |
|---|---|---|---|
| Nifty 50 | Thursday | Last Thursday of month | Cash settled |
| Bank Nifty | Thursday | Last Thursday of month | Cash settled |
| Sensex | Friday | Last Thursday of month | Cash settled |
| FinNifty | Friday | Last Thursday of month | Cash settled |
Physical Delivery vs Cash Settlement & ITM/OTM Behaviour on Expiry
All index options on NSE are cash‑settled — there is no physical delivery of shares, so the final payout is simply the difference between the strike and the closing index value multiplied by the lot size (check the NSE F&O lot size list for exact multipliers). If your option expires ITM, the exchange automatically credits/debits the intrinsic value to your account; OTM options expire worthless and the premium you paid is lost. Remember, the last 30 minutes on expiry day often see a “gamma squeeze” as market makers hedge their books — stay disciplined and avoid chasing the closing tick.
Actionable Investor Takeaways
- Mark the weekly expiry calendar for each index you trade; a missed Thursday or Friday can wipe out a week’s premium.
- Use the Greeks calculator to estimate theta decay and gamma risk before entering a weekly position.
- Prefer monthly contracts for directional bets with a longer horizon; they give you breathing room against intraday noise.
- Always verify lot sizes and margin requirements via the official NSE tools before sizing any trade.
Frequently Asked Questions
Q1: Which index expires on Monday?
None of the major NSE indices (Nifty, Bank Nifty, Sensex, FinNifty) have a Monday weekly expiry; they expire on Thursday or Friday as per the schedule above.
Q2: What is FinNifty?
FinNifty is the Nifty Financial Services Index, comprising 20 financial sector stocks; it follows a Friday weekly expiry and a monthly expiry on the last Thursday.
Q3: How to trade in Sensex options?
Open a derivative‑enabled trading account, ensure you have the required margin (use the margin calculator), and select Sensex weekly (Friday) or monthly (last Thursday) contracts from your broker’s option chain.
Q4: What happens to an ITM Nifty option on expiry day?
The exchange automatically exercises the option and credits the intrinsic value (strike‑index difference × lot size) to your account; no action is needed from you.
