Mock Trading for Closing Auction Session Implementation
NSE circular NSE/CMTR/75479 · 30 Jul 2026
Official title
Mock trading on Saturday, August 01, 2026 - Go Live of trading modalities related to Introduction of Closing Auction Session (CAS) in Equity Cash segment - New version of NEAT+ 7.8.9
Official record
Open source pageSummary
Check the official recordWhat changed
The National Stock Exchange of India (NSE) will conduct a mock trading session on August 1, 2026, to test trading modalities for the upcoming Closing Auction Session (CAS) in the Equity Cash segment. Members are required to upgrade to the new NEAT+ version 7.8.9, which will be available for download on July 31, 2026. The CAS-related changes will go live in the production environment on August 3, 2026. Members must download updated master files on August 1, 2026, and are encouraged to participate in all three mock trading sessions to ensure system readiness. Existing NEAT+ version 7.8.8 will be discontinued after September 5, 2026.
What you must do
- Upgrade to NEAT+ version 7.8.9 for CAS-related trading
- Download and load updated master files before the mock session
- Participate in mock trading sessions and perform live re-login
Document text
National Stock Exchange of India Limited
Circular
| Department: CAPITAL MARKET SEGMENT | |
|---|---|
| Download Ref No: NSE/CMTR/75479 | Date: July 30, 2026 |
| Circular Ref. No: 108/2026 |
All Members,
Mock trading on Saturday, August 01, 2026 – Go Live of Trading modalities related to Introduction of Closing Auction Session (CAS) in Equity Cash segment - New version of NEAT+ 7.8.9
Members are required to note that the changes in trading modalities in the Equity segment due to introduction of Closing Auction Session (CAS), shall be effective in LIVE from August 03, 2026. Following circulars were issued by Exchange:
| Particulars | Reference number & date | Subject |
|---|---|---|
| Circulars | NSE/CMTR/73362 dated March 18, 2026 | Operational guidelines and Standard Operating Procedure (SOP) on Introduction of Closing Auction Session (CAS) in the Equity Cash Segment |
| NSE/CMTR/73845 dated April 22, 2026 | Modification in Security master files on account of Introduction of Closing Auction Session (CAS) in the Equity Segment | |
| NSE/CMTR/74466 dated May 29, 2026 | Introduction of Closing Auction Session (CAS) in the Equity Cash segment - Change in trading modalities in the Equity Derivatives segment | |
| FAQ path | https://www.nseindia.com/static/trade/continuous-markets-FAQs > Closing Auction Session (CAS) in Equity segment(CM) and changes in Equity Derivatives (F&O) Segment |
In continuation to circular (Download No. 71999) dated December 24, 2025, Exchange shall be conducting a mock trading session in the Capital Market segment on Saturday, August 01, 2026. In alignment with above changes, Exchange shall introduce a new NEATPlus version (7.8.9). It is recommended that members must use NEATPlus version 7.8.9 from August 01, 2026 for CAS related changes.
| Mock Date: August 01, 2026 | |
|---|---|
| Particulars | Time in Hrs |
| Trading Session-1 from Primary site | |
| Morning Block Deal Window Session-1 open time | 07:30 |
| Morning Block Deal Window Session-1 close time | 07:45 |
| Pre-Open open time | 07:45 |
| Pre-Open* close time * Random closure in last one minute | 07:53 |
| Special Preopen Session open time (For IPO & Relisted security) | 07:45 |
| Special Preopen Session** close time (For IPO & Relisted security) ** Random closure in last ten minute | 08:30 |
| Normal Market open time | 08:00 |
| T+0 Market Open time | 08:00 |
| Call Auction Illiquid session open time (2 sessions of 30 min each)* * Random closure in last one minute | 08:15 |
| 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 | 08:45 |
| Auction Market Open Time | 08:30 |
| Auction Market Close Time | 09:15 |
| Block Deal Window Session – 2 Open time | 08:30 |
| Block Deal Window Session – 2 Close time | 08:45 |
| Contingency Start time | 08:45 |
| Contingency End time | 09:55 |
| Normal Market close time | 10:00 |
| Mock Date: August 01, 2026 | |
| Particulars | Time in Hrs |
| Trading Session-2 from DR Site | |
| Pre-Open open time | 10:30 |
| Pre-Open* close time * Random closure in last one minute | 10:38 |
| Normal Market open time | 10:45 |
| Call Auction Illiquid session open time (1 session of 30 min)* * Random closure in last one minute | 11:00 |
| Normal Market close time for CAS securities. | 11:30 |
| CAS Open time | 11:35 |
| CAS Market order restriction start time | 11:40 |
| CAS close time * * Random closure in last two minute | 11:45 |
| Normal Market close time | 11:45 |
| Closing Session open time | 12:05 |
| Closing Session close time | 12:15 |
| Trade modification end time | 12:25 |
| Mock Date: August 01, 2026 | |
| Particulars | Time in Hrs |
| Trading Session-3 from Primary site | |
| Block Deal Window Session open time | 13:45 |
| Block Deal Window Session close time | 14:00 |
| Pre-Open open time | 14:00 |
| Pre-Open* close time * Random closure in last one minute | 14:08 |
| Normal Market open time | 14:15 |
| Call Auction Illiquid session open time (2 session of 15 min each)* * Random closure in last one minute | 14:30 |
| T+0 Market Open time | 14:15 |
| T+0 Market Close time | 14:45 |
| T+0 Market Trade modification end time | 14:50 |
| Auction Market Open Time | 14:30 |
| Auction Market Close Time | 15:15 |
| Normal Market close time for CAS securities. | 15:15 |
| CAS Open time | 15:20 |
| CAS Market order restriction start time | 15:25 |
| CAS close time * * Random closure in last two minute | 15:30 |
| Normal Market close time | 15:30 |
| Closing Session open time | 15:50 |
| Closing Session close time | 16:00 |
| Trade Modification end time | 16:10 |
| Re-login Timings | |
| Live Re-login start time | 20:00 |
| Live Re-login close time | 21:00 |
#Trades from trading session 1 & 2 shall not be available in trading session 3. However, Trades from trading session 1 shall be available in trading session 2. Members are requested to actively participate in all trading sessions.
Members are advised to take note of the below important instructions:
- Below new NEAT+ version should be used explicitly for CAS:
| Version | Availability | Download path on NSE Extranet path |
|---|---|---|
| NEAT+ 7.8.9 | On July 31, 2026, 18:00 hours | /cmftp/common/NEATPlus789 |
- The existing NEAT+ exe version shall be discontinued as per below:
| Version | Download path on NSE Extranet path | Discontinuation date |
|---|---|---|
| 7.8.8 | /cmftp/common/NEATPlus788 | September 05, 2026 (mock) |
- For mock session on August 1, 2026 and Live trading on August 3, 2026, kindly download the master files which will be generated by Exchange post completion of end of trading day activities. The files shall be available on the extranet path on August 01, 2026 on or before 6:00 hours:
| File name | Location | File availability |
|---|---|---|
| security.gz | /cmftp/common/ntneat | On August 01, 2026 by 06:00 hours |
| participant.gz | ||
| nnf_security.gz | ||
| nnf_participant.gz | ||
| NSE_CM_security_31072026.csv.gz | ||
| cm_contract_stream_info.csv | /cmftp/common/tbt_masters |
Members are advised to load the above master files in the trading application before Mock trading session on August 01, 2026.
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
| Toll Free No | Email id |
|---|---|
| 1800-266-0050 (Option 1) | msm@nse.co.in |
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 & 7.8.9 |
| Order Purge: | All outstanding orders will be cleared before each session. Members using NNF software must manually clear orders in their systems. |
| 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. |
| Extranet / Member portal availability | Connect2NSE and Extranet facility shall not be available from 14:30 hours till end of mock session. Extranet API shall not be available from 14:30 to 15:30 hours. |
| Participation: | Members should participate using all trading software and re-login into live environment to ensure smooth connectivity for Monday August 03, 2026. |
| Live Updates: | Visit www.nseindia.com for any session-related updates. |
| Support: | For queries, call Toll-Free: 1800 266 0050 (Option 1). |
Source details
- Source
- National Stock Exchange of India
- Type
- circular
- Published by source
- 30 Jul 2026
- Document number
- NSE/CMTR/75479
- Issuing division
- CAPITAL MARKET SEGMENT
- Effective date
- 03 Aug 2026
- Coverage area
- securities