About 1 trading day's worth of time, not 3 days. Time value pays for moves the index might make. Over a weekend the market is shut, so the index can only jump once, at Monday's open. This market counts that jump as about 1 trading day of time. Near expiry, even that 1 day costs a lot.
- Index
- NIFTY
- Cycle
- NIFTY weekly
- Starts
- 09:15 IST
- Runs for
- 2 trading days · About 23 min at Normal speed
- Difficulty
- Intermediate
- Date
- 19 Jun 2026
- Expiry
- NIFTY 23 Jun 2026
- IV
- 12.5%
What is this market shaped like?
The market starts on the Friday of a NIFTY week, 2 trading days before the Tuesday expiry. It runs all Friday, then Monday until 10:15. Monday opens with a gap. A gap means the first price can be far from Friday's last price. An at-the-money option has the strike closest to the index.
What is left of an at-the-money call's price, if nothing moves
| When | Left of Friday's opening price |
|---|---|
| Friday open | 100% |
| Friday close | 89% |
| Monday open | 72% |
| Monday 10:15 | 66% |
Nothing moves means the index stays still and IV stays the same. IV (implied volatility) is the size of move option prices expect.
From Friday's close to Monday's open, the call loses about 19% of its Friday-close price. That is more than Friday took, because each day nearer expiry costs more. If the weekend counted as 3 full trading days, the call would lose about 34% instead. Market X-Ray counts every calendar day, weekends too, so it shows an even bigger drop.
What will you see?
- Monday's first price may jump up or down from Friday's close. Both the index and option prices can open with a gap.
- Theta is how much an option's price falls from time alone. Over the weekend it is taken at Monday's open, when trading starts again.
- IV has no planned change. Monday's first 30 minutes are a bit busier than usual.
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.
- Near Friday's close, buy 1 lot of the at-the-money call and 1 of the at-the-money put.
- Note both prices at Friday's close.
- At Monday's open, note them again, and NIFTY's gap. If nothing had moved, both together would have lost about 15%.
What should you check afterwards?
- Together, did the call and the put lose more or less than 15%?
- Which one gained from the gap, and did the gain beat the weekend's loss?
Open these next: