NIFTY expiry 19 Oct 2026: what the 22,900 options did
On Monday 19 October 2026 the NIFTY strike nearest the index at 15:00 was 22,900. The index went from 22,890 at 15:00 to 22,889 at 15:30, down 1 points across the settle walk.
The at-the-money legs, 15:00 to 15:30
| Leg | 15:00 | High | Low | 15:30 | End vs 15:00 | Open interest |
|---|---|---|---|---|---|---|
| 22,900 CE | ₹22.0 | ₹46.2 15:25 | ₹0.1 15:30 | ₹0.1 | worthless | 36.6M → 26.8M |
| 22,900 PE | ₹35.9 | ₹61.6 15:08 | ₹1.4 15:26 | ₹11.1 | 0.3× | 19.8M → 18.0M |
Premium of the strike nearest the index at 15:00, sampled every ten seconds from the NSE option chain. Index values are the chain's own quote. Dotted verticals mark a pin-book flip on Gamma Terrain.
What happened
The 22,900 call was ₹22.0 at 15:00. It reached ₹46.2 at 15:25, 2.1× its 15:00 price. Its low was ₹0.1 at 15:30, less than half of where it started the half hour. It ended at ₹0.1, worthless. Open interest at the strike went from 36.6 million to 26.8 million, so positions were closed through the window.
The 22,900 put was ₹35.9 at 15:00. Its high was ₹61.6 at 15:08. Its low was ₹1.4 at 15:26, less than half of where it started the half hour. It ended at ₹11.1, 0.3× the 15:00 price.
Gamma Terrain's pin-book read flipped: at 15:30 the resting depth read the put strikes below the pin thinning (puts 23 %, calls 15812 % of their baseline). A flip names the side whose book is emptying. Across 45 sessions it has not been a direction tell, it is a vacuum tell.
For context, across 21 NIFTY and SENSEX expiries measured to 2026-09-08, 15 of 42 at-the-money legs doubled at some point in this window, 26 lost half, and 13 ended at or above their 15:00 price. This page states what the tape did. It is not a recommendation to buy or sell anything.
Gamma Terrain shows the pin, the walls, the book read and every large print, tick by tick, on NIFTY and SENSEX.
The recap is the after-photo. The terrain is the window while it happens.
Read every panel behind these numbers, chapter by chapter.
Trading by the Numbers walks through the quantitative reads behind a modern F&O dashboard — order-flow imbalance, footprints, VWAP bands, OI flow, gamma structure and the expiry endgame — in plain trader-to-trader language.