Changes to the Pre-Open Session in Equity & Equity Derivatives w.e.f. 7th Sep'26

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The Pre-Open Session framework has been modified to align with the Closing Auction Session (CAS) framework. The changes are applicable to the Equity and Equity Derivatives segments.

The overall Pre-Open Session will continue to run from 9:00 AM to 9:15 AM. However, the Order Entry and Order Matching phases have been revised, with specific changes to the types of orders that can be entered, modified or cancelled during the session.

Relevant Circulars: NSE/CMTR/74969, NSE/FAOP/74970, BSE/20260803-35, BSE/20260803-36

Here’s a detailed overview of the changes.

What is changing in the Pre-Open Session?

The key changes include:

  • Revised Order Entry Period structure.

  • Market orders will be allowed for entry, modification and cancellation only during the initial 9:00 AM – 9:05 AM period.

  • From 9:05 AM onwards, only Limit Orders can be entered, modified or cancelled.

  • No modification or cancellation will be allowed for Market Orders after 9:05 AM.

  • The Order Entry Period will be subject to system-driven random closure in the last 2 minutes.

  • The Order Matching & Trade Confirmation Period will start immediately after the Order Entry Period ends.

  • The overall Pre-Open Session will continue to end at 9:15 AM, followed by the Continuous Trading Session (CTS).

1. Revised Pre-Open Session Timings

The Pre-Open Session will continue to operate through a Call Auction mechanism for a total duration of 15 minutes, from 9:00 AM to 9:15 AM.

While the overall session timing remains unchanged, the Order Entry and Order Matching periods have been revised.

Current vs. Revised Framework

Session Current Time Revised Time What Changes?
Order Entry Period 9:00 AM – 9:08 AM* 9:00 AM – 9:05 AM Order entry, modification and cancellation allowed for Limit & Market Orders
Order Entry Period – Limit Orders — 9:05 AM – 9:10 AM* Only Limit Orders can be entered, modified or cancelled. No modification/cancellation of Market Orders
Order Matching & Trade Confirmation 9:08 AM# – 9:12 AM 9:10 AM# – 9:12 AM Opening price determination, order matching and trade confirmation
Buffer Period 9:12 AM – 9:15 AM 9:12 AM – 9:15 AM No change – Transition from Pre-Open to Continuous Trading Session (CTS)

*System-driven random closure: The Order Entry Period is subject to random closure in the last 2 minutes.

#Order matching period will start immediately after completion of order entry period.

2. For which securities is Pre-Open applicable in the Equity Market?

The Pre-Open Session with the Call Auction mechanism is applicable to all equity market securities, including:

  • Equity securities

  • SME securities

  • Partly paid-up securities

  • InvITs (Infrastructure Investment Trusts)

  • REITs (Real Estate Investment Trusts)

3. For which instruments is Pre-Open applicable in the Equity Derivatives Market?

In the Equity Derivatives segment, the Pre-Open Session is applicable to:

  • Single Stock Futures

  • Index Futures

The Pre-Open Session is applicable to futures contracts and not to options contracts.

4. Which Futures Contracts are Eligible?

The Pre-Open Session applies to current-month (M1) futures on Single Stocks and Indices. During the last five trading days before M1 expiry, it is also extended to next-month (M2) futures.

Illustration

Assume M1 expires on 30-Dec-2025 and M2 expires on 27-Jan-2026:

Trading Date M1 M2 Pre-Open Applicability
01-Dec to 21-Dec Yes No M1 only
22-Dec Yes No M1 only
23-Dec Yes Yes M1 & M2
24-Dec Yes Yes M1 & M2
25-Dec Holiday Holiday —
26-Dec Yes Yes M1 & M2
27-Dec Holiday Holiday —
28-Dec Holiday Holiday —
29-Dec Yes Yes M1 & M2
30-Dec – Expiry Day Yes Yes M1 & M2
31-Dec onwards Expired Yes M2 becomes current month

Note: From 31-Dec-2025, M2 becomes the current-month contract. The next-month contract will then be the February 2026 futures contract, expiring on 24-Feb-2026.

Key Takeaways

  • The overall Pre-Open Session remains unchanged at 9:00 AM – 9:15 AM.

  • The Order Entry Period has been restructured.

  • From 9:00 AM to 9:05 AM, both Market and Limit Orders can be entered, modified and cancelled.

  • From 9:05 AM onwards, only Limit Orders can be entered, modified and cancelled.

  • Market Orders cannot be modified or cancelled after 9:05 AM.

  • The Order Entry Period is subject to system-driven random closure in the last 2 minutes.

  • Order Matching starts immediately after the Order Entry Period ends.

  • The Buffer Period remains unchanged at 9:12 AM – 9:15 AM.

  • The framework applies to Equity Market securities, including SME securities, partly paid-up securities, InvITs and REITs.

  • In Equity Derivatives, it applies to Single Stock Futures and Index Futures.

  • Current-month futures are eligible, while next-month futures are additionally included during the last five trading days before current-month expiry.