Mock Trading for Closing Auction Session Testing in Equity Cash Segment
NSE circular NSE/CMTR/75401 · 24 Jul 2026
Official title
Mock trading on Saturday, July 25, 2026 - Testing of Trading modalities related to Introduction of Closing Auction Session (CAS) in Equity Cash Segment - Update
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The National Stock Exchange of India is conducting a mock trading session on July 25, 2026, to test trading modalities for the introduction of the Closing Auction Session (CAS) in the Equity Cash segment. The session is divided into three parts. Trading Session-1 requires the use of NEATPlus version 7.8.9, while Sessions 2 and 3 require reverting to version 7.8.8. Members must load specific master files for Session-1 and use end-of-day files from July 24, 2026, for subsequent sessions. Participation is open to all Capital Market segment members. Trades executed during the mock session carry no financial obligations. Members are advised to actively participate to ensure connectivity for live trading on July 27, 2026.
What you must do
- Use NEATPlus version 7.8.9 for Trading Session-1 and version 7.8.8 for Trading Sessions 2 and 3.
- Load specific master files for Trading Session-1 and use July 24, 2026 EOD files for other sessions.
Key dates
Document text
National Stock Exchange of India Limited
Circular Department: CAPITAL MARKET SEGMENT Download Ref No: NSE/CMTR/75401 Date: July 24, 2026 Circular Ref. No: 106/2026
All Members,
Mock trading on Saturday, July 25, 2026 – Testing of Trading modalities related to Introduction of Closing Auction Session (CAS) in Equity Cash segment - Update
Members are required to note that this circular supersedes the mock circular NSE/CMTR/75366 issued on July 23, 2026 and are requested to consider the below updated mock session timings and other details as follows:
With reference to circular no. NSE/CMTR/74466 dated May 29, 2026 regarding ‘Introduction of Closing Auction Session (CAS) in the Equity Cash segment - trading modalities’, Exchange will be conducting a mock trading session in the Capital Market on Saturday, July 25, 2026.
Further, Exchange shall be introducing new NEATPlus version (7.8.9) for aforesaid CAS implementation related testing. Members must note that said new NEATPlus version shall be applicable only during the Trading Session-1 of the mock. Post Trading session 1, members shall have to reinstall and login with earlier NEATPlus version (7.8.8) for Trading Session – 2 & 3 which shall be conducted as per existing Trading modalities without changes related to CAS. Kindly refer point A, and B for more information.
Mock Date: July 25, 2026
| Particulars | Time in Hrs |
|---|---|
| Trading Session-1 | |
| Morning Block Deal Window Session-1 open time | 07:45 |
| Morning Block Deal Window Session-1 close time | 08:00 |
| Pre-Open open time | 08:00 |
| Pre-Open* close time * Random closure in last one minute | 08:08 |
| Special Preopen Session open time (For IPO & Relisted security) | 08:00 |
| Special Preopen Session** close time (For IPO & Relisted security) ** Random closure in last ten minute | 08:45 |
National Stock Exchange of India Limited Page 2 of 6
| Particulars | Time in Hrs |
|---|---|
| Normal Market open time | 08:15 |
| T+0 Market Open time | 08:15 |
| Call Auction Illiquid session open time (2 sessions of 30 min each)* * Random closure in last one minute | 08:30 |
| T+0 Market Close time | 08:40 |
| T+0 Market Trade modification end time | 08:45 |
| Normal market open time for stocks in special preopen session | 09:00 |
| Auction Market Open Time | 08:30 |
| Auction Market Close Time | 09:15 |
| Normal Market close time for CAS securities. | 09:00 |
| CAS Open time | 09:05 |
| CAS Market order restriction start time | 09:50 |
| CAS close time * * Random closure in last two minute | 10:35 |
| Normal Market close time | 10:35 |
| Closing Session open time | 10:45 |
| Closing Session close time | 10:55 |
| Trading Session-2 from Primary Site | |
| Block Deal Window Session open time | 13:00 |
| Block Deal Window Session close time | 13:15 |
| Pre-Open open time | 13:15 |
| Pre-Open* close time * Random closure in last one minute | 13:23 |
| Special Preopen Session open time (For IPO & Relisted security) | 13:15 |
| Special Preopen Session** close time (For IPO & Relisted security) ** Random closure in last ten minute | 14:00 |
| Normal Market open time | 13:30 |
| T+0 Market Open time | 13:30 |
| Call Auction Illiquid session open time (2 sessions of 1 hour each)* * Random closure in last one minute | 13:30 |
| T+0 Market Close time | 14:30 |
| T+0 Market Trade modification end time | 14:40 |
| Normal market open time for stocks in special preopen session | 14:15 |
| Auction Market Open Time | 14:15 |
| Auction Market Close Time | 15:00 |
| Block Deal Window Session Open time | 14:45 |
| Block Deal Window Session Close time | 15:00 |
| Normal Market close time | 15:15 |
National Stock Exchange of India Limited Page 3 of 6
| Particulars | Time in Hrs |
|---|---|
| Trading Session-3 from DR Site | |
| Pre-Open open time | 16:00 |
| Pre-Open* close time * Random closure in last one minute | 16:08 |
| Normal Market open time | 16:15 |
| Call Auction Illiquid session open time (1 session of 15 mins)* * Random closure in last one minute | 16:15 |
| Normal Market close time | 17:00 |
| Closing Session open time | 17:10 |
| Closing Session close time | 17:20 |
| Trade Modification end time | 17:30 |
| Re-login Timings | |
| Live Re-login start time | 19:00 |
| Live Re-login close time | 19:30 |
#Trades from trading session 1 shall not be available in trading session 2 & 3. However, Trades from trading session 2 shall be available in trading session 3. Members are requested to actively participate in all trading sessions.
Members are advised to take note of the below important instructions:
A) Testing of Closing Auction Session (CAS) (Trading session - 1)
➢ Below NEAT+ version should be used explicitly for mock session 1 only:
| Version | Availability | Download path on NSE Extranet path |
|---|---|---|
| NEAT+ 7.8.9 | On July 25, 2026, 07:00 hours | /cmftp/common/ Mock/CM/25JULY2026/NEATPlus789 |
➢ The master files applicable for Trading Session-1 (i.e. security.gz, nnf_security.gz & NSE_CM_security_25072026.csv.gz) will be made available to trading members on the NSE Extranet (Path: /cmftp/common/Mock/CM/25JULY2026) on July 25, 2026 on or before 7:00 hours. All other master files which were generated by Exchange post completion of end of trading day activities on July 24, 2026 shall be applicable for the mock trading session. ➢ Members are advised to load the above master files in the trading application before Mock trading session 1 on July 25, 2026.
B) For mock session 2,3 and Live trading from July 27, 2026, kindly use below NEAT+ version (i.e. 7.8.8) & download the master files which were generated by Exchange post completion of end of trading day activities on July 24, 2026:
National Stock Exchange of India Limited Page 4 of 6
| Version | Download Path on NSE Extranet: |
|---|---|
| 7.8.8 | /cmftp/common/NEATPlus788 |
| File name | Location | EOD File Date |
|---|---|---|
| security.gz | /cmftp/common/ntneat | July 24, 2026 |
| participant.gz | ||
| nnf_security.gz | ||
| nnf_participant.gz | ||
| NSE_CM_security_24072026.csv.gz | ||
| cm_contract_stream_info.csv | /cmftp/common/tbt_masters |
For other important instructions regarding the mock trading, kindly refer to the following Annexures: Annexure 1: Important instructions regarding mock trading session. Annexure 2: Pre-requisites / General guidelines for participating in the Mock environment. Annexure 3: Important guidelines in case of switchover of trading system to Disaster Recovery (DR) Site.
For and on behalf of National Stock Exchange of India Limited
Khushal Shah Associate Vice President
Annexure – 1 Important instructions regarding mock trading session
| Particulars | Details |
|---|---|
| Connectivity Parameters: | Refer to circular NSE/MSD/73993 dated April 30, 2026 & NSE/MSD/74511 dated June 02, 2026 for interactive connectivity details. |
| Installation Guide: | Available on NSE Extranet at /common/InstallationProcedure. |
| Software Version: | NEAT+ 7.8.8 |
| Order Purge: | All outstanding orders will be cleared before each session. Members using NNF software must manually clear orders in their systems. |
| Toll Free No | 1800-266-0050 (Option 1) |
| Email id | msm@nse.co.in |
National Stock Exchange of India Limited Page 5 of 6
| Particulars | Details |
|---|---|
| Software Testing: | Refer to circular NSE/MSD/46441 and SEBI circular SEBI/HO/MRD1/DSAP/CIR/P/2020/234. Members may use either Mock Trading or Simulated Environment to meet regulatory requirements. |
| No Financial Obligation: | Trades during mock sessions will not result in any fund pay-in or pay-out. |
| UCC/PAN Validity: | Only valid and compliant UCC/PAN uploaded and approved before cutoff will be allowed. For queries, contact uci@nse.co.in. UCC Validation will be skipped during contingency time for order entry. |
| NOTIS Availability: | NOTIS application will be accessible during the mock session -2. |
| Participation: | Members should participate using all trading software and re-login into live environment to ensure smooth connectivity for Monday July 27, 2026. |
| Live Updates: | Visit www.nseindia.com for any session-related updates. |
| Support: | For queries, call Toll-Free: 1800 266 0050 (Option 1). |
Annexure – 2 Pre-requisites / General guidelines for participating in the Mock environment
| Pre-requisites / General guidelines Heads | Details |
|---|---|
| Eligibility | All members enabled for trading in the Capital Market (CM) segment in the live market are automatically eligible for mock trading. Participation is enabled using existing User IDs, IPs, and Box ID mappings from the live environment. |
| Telnet Connectivity | Ensure you can successfully telnet the Exchange host from the IP address you intend to use. |
| Box ID Setup | Confirm that the Box ID is created on the IP with appropriate messages for the segment you wish to trade in. |
| NNF Application Users | If using Non-NEAT Frontend (NNF): a) User ID must be of dealer type. b) It must be converted for NNF. C) It must be mapped with the IP. |
| Branch/User Limits | Set appropriate branch and user limits from the Corporate Manager Terminal before placing orders in the mock session. |
National Stock Exchange of India Limited Page 6 of 6
| Pre-requisites / General guidelines Heads | Details |
|---|---|
| Exchange Requests for Mock Participation | Send email requests for the following actions with User ID and segment details: a) Pro Enablement b) CTCL Conversion (only dealer IDs) c) Password Reset for Corporate Manager User ID d) Unlocking of Corporate Manager User ID e) Change of Trading Rights (e.g., PRO to CLI, PRO+CLI) |
| Password Management | Corporate Manager User ID: Exchange will assist with reset/unlock via email. Other User IDs: Members must reset/unlock these themselves using the Corporate Manager Terminal. |
Annexure – 3 Important guidelines in case of switchover of trading system to Disaster Recovery (DR) Site
- Kindly note below points after switch over to DR site: a. Trades of primary site will be available in Previous Trades window. b. Trades can be modified/cancelled using Multiple Trade Modification and Cancellation window respectively. c. Messages of primary site will be available in TWS Message Area.
- If user renames or deletes the User folder and re-login the NEAT+ terminal, then data of primary site shall not be available in the functional window as mentioned above point.
Source details
- Source
- National Stock Exchange of India
- Type
- circular
- Published by source
- 24 Jul 2026
- Document number
- NSE/CMTR/75401
- Issuing division
- CAPITAL MARKET SEGMENT
- Coverage area
- securities