They fall fast, and they react hard to the index. NIFTY weekly options expire at Tuesday's close. An option in the money then pays the gap between the index and its strike. Every other option ends at zero. Take an at-the-money call, whose strike is closest to the index. If nothing moves, it keeps about 58% of its opening price at 13:30.
- Index
- NIFTY
- Cycle
- NIFTY weekly
- Starts
- 13:30 IST
- Runs for
- 1 trading day · About 7 min at Normal speed
- Difficulty
- Intermediate
- Date
- 18 Aug 2026
- Expiry
- NIFTY 18 Aug 2026
- IV
- 12.5%
What is this market shaped like?
The market is a single NIFTY expiry Tuesday. Most versions start at the open. The From 13:30 version joins for the last part of the day. In this market an expiry day counts as a little more than a normal day. Its last hour is busier.
What is left of an at-the-money call's price, if nothing moves
| When | Left of Tuesday's opening price |
|---|---|
| Tuesday open | 100% |
| 12:00 | 69% |
| 13:30 | 58% |
| 14:30 | 45% |
| 15:00 | 34% |
| 15:30 | 15% |
Nothing moves means the index stays still and IV stays the same. IV (implied volatility) is the size of move option prices expect.
At the close, time value is gone. Time value is the part of the price that pays for the time left. Only the in-the-money gap stays.
What will you see?
- Delta is how much an option moves for each point the index moves. Gamma is how fast delta changes. On expiry day gamma is large near the money, so a small index move can swing a price a lot.
- Options that were cheap in the morning often end at zero. An option near the money can double, or fall to almost nothing, in the last 2 hours.
- In the Nervous version, at 11:45 the index falls 0.9% in 10 minutes. IV goes up by 2.5 points, for example from 15% to 17.5%. The gap between buy and sell prices grows too.
- In the Both indices version, BANKNIFTY does not expire. For BANKNIFTY it is an ordinary Tuesday.
Which version do you want?
Each version is the same kind of market with 1 thing changed. Choose one to start it.
What should you try?
Try this with 1 lot of a call and 1 of a put. A lot is the smallest size you can trade.
- At 13:30, pick the at-the-money call and the at-the-money put.
- Buy 1 lot of each, then write down both prices every 30 minutes.
- Let them run to the close and see what each pays.
What should you check afterwards?
- How far did NIFTY move after 13:30, and which option gained from it?
- Did the one that gained make up for the one that lost?
Open these next: