TBTflow / Expiry recaps / NIFTY gamma blast today
NIFTY gamma blast today · from tick data

NIFTY gamma blast today: what the 22,900 options did after 15:00 on the 19 October 2026 expiry

Next NIFTY expiry: Tuesday 27 October 2026; the one after: Tuesday 3 November 2026. From the exchange's F&O contract list.

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.

Shown: the latest NIFTY expiry, Monday 19 October 2026. NIFTY weekly options expire on Tuesdays (a day earlier when that day is a market holiday); this page switches to the new expiry from 15:00 IST that day. Permanent page for this expiry: NIFTY 19 October 2026. SENSEX: SENSEX gamma blast today.

The at-the-money legs, 15:00 to 15:30

Leg15:00HighLow15:30End vs 15:00Open interest
22,900 CE₹22.0₹46.2 15:25₹0.1 15:30₹0.1worthless36.6M → 26.8M
22,900 PE₹35.9₹61.6 15:08₹1.4 15:26₹11.10.3×19.8M → 18.0M
₹0₹10₹20₹30₹40₹50₹6015:0015:0515:1015:1515:2015:2515:30book flip 15:30₹46.2₹61.622900 CE22900 PE

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.

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.

Earlier NIFTY expiries

Side by side: NIFTY expiry analysis, the last five · every expiry: expiry recaps.

Quick questions

Did gamma blast happen today in NIFTY?
On the Monday 19 October 2026 NIFTY expiry the 22,900 call went from ₹22.0 at 15:00 to a high of ₹46.2 at 15:25 (2.1×) and ended at ₹0.1; the 22,900 put went from ₹35.9 at 15:00 to a high of ₹61.6 at 15:08 (1.7×) and ended at ₹11.1. A leg that at least doubled is what traders call a gamma blast. This page is refreshed every NIFTY expiry from 15:00 IST.
What is a gamma blast?
On expiry day an at-the-money option has very little time value left, so its price reacts sharply to small moves in the index. When the index moves in the last hour, a cheap at-the-money option can multiply in minutes; that sudden jump is called a gamma blast.
What time does gamma blast happen in NIFTY?
Mostly in the last hour of the expiry day, and most sharply between 15:00 and 15:30 IST, when the exchange settles the index on the average of that half hour. NIFTY weekly options expire on Tuesdays.
Is gamma blast predictable?
Not reliably. Across 21 NIFTY and SENSEX expiries measured to 2026-09-08, 15 of 42 at-the-money legs doubled at some point after 15:00, 26 lost half, and 13 ended at or above their 15:00 price. Losing days are shown here the same way as winning days.
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Gamma Terrain shows the pin, the walls, the book read and every large print, tick by tick, on NIFTY and SENSEX.

This page is the after-photo. The terrain is the window while it happens.

These pages describe market activity. They are not investment advice and not a recommendation to buy or sell any option. TBTflow is not registered with SEBI.

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