What Is Option Expiry?
Option expiry is the date on which an options contract ceases to be valid. After the expiry date, an option cannot be exercised and all remaining time value drops to zero. If the option is in-the-money at expiry, it is settled for its intrinsic value (cash settlement in India). If out-of-the-money at expiry, it expires worthless and the entire premium paid by the buyer is lost. Expiry is one of the most important events in the F&O calendar.
Expiry Schedule on NSE India
| Contract Type | Expiry Day | Available Contracts |
|---|---|---|
| Nifty 50 options | Every Thursday | Weekly; current week + 3 weekly + monthly |
| Bank Nifty options | Every Wednesday | Weekly; current week + 3 weekly + monthly |
| Monthly options (index and stocks) | Last Thursday of month | Current month + 2 far months |
| Individual stock options | Last Thursday of month | Monthly only |
What Happens on Expiry Day?
- In-the-money (ITM) options are automatically exercised and settled in cash at the difference between the final settlement price (closing price of the underlying) and the strike price.
- Out-of-the-money (OTM) options expire worthless; the buyer loses the entire premium.
- Expiry day (especially Thursday for Nifty) typically sees extremely high volatility and trading volume as positions are closed, hedges are unwound, and new contracts for the next expiry are opened.
Expiry Day Strategies
Due to maximum time decay (theta = 0 at expiry), options buyers have the least to gain on expiry day. Options sellers (writers) benefit from premium collection as OTM options decay rapidly. Short straddle or strangle strategies (selling both call and put at the same strike) are popular on expiry day in Indian markets, but carry the risk of sudden sharp moves in either direction.
Rolling Positions Before Expiry
Traders who want to maintain a position beyond expiry must "roll" it: buy back the expiring contract and simultaneously open a new contract in the next expiry cycle. This involves closing a position that may have time value left and opening the next month's or week's contract at the current premium level.
Key Takeaway
Option expiry is the moment of truth for all open options positions: ITM options pay out, OTM options expire worthless. Expiry day's high volatility and rapid time decay create both opportunities and risks for experienced traders. Beginners should avoid trading on expiry day until they thoroughly understand how expiry mechanics affect premiums. Use the Lemonn app to track expiry calendars and monitor open interest data to understand market positioning before each expiry.
