Description

NSE will conduct mock trading session from Primary and BCP/DR sites on December 20, 2025, followed by re-login session to avoid login issues on December 22, 2025.

Summary

NSE will conduct a mock trading session on Saturday, December 20, 2025 from both Primary and BCP/DR sites. The mock session will include non-graceful shutdown from primary site to DR site, followed by a live re-login session from the Primary site to prevent login problems on Monday, December 22, 2025. All members are required to participate and follow specific operational instructions.

Key Points

  • Mock trading scheduled for December 20, 2025 with two sessions: Trading Session-1 from Primary Site and Trading Session-2 from DR Site
  • Non-graceful shutdown will occur when exchange shifts from primary to DR site during mock session
  • All outstanding orders will be purged before BCP site trading starts
  • Multicast TBT sequence numbers will restart from ‘1’ when trading begins from BCP site
  • Live re-login session scheduled from 18:30 to 19:00 to avoid Monday login issues
  • No changes required in NEAT Adapter settings - members should retain Friday December 19, 2025 settings
  • Latencies for Colo Participants will differ on DR/BCP day compared to normal trading

Trading Session Schedule

Session-1 from Primary Site:

  • Morning Block Deal Window: 08:45 - 09:00
  • Pre-Open: 09:00 - 09:08 (random closure in last minute)
  • Special Pre-open for IPO/Relisted: 09:00 - 09:45 (random closure in last 10 minutes)
  • Normal Market Open: 09:15
  • T+0 Market Open: 09:15
  • Call Auction Illiquid: 09:30 (2 sessions of 1 hour each)
  • Normal Market Open for special pre-open stocks: 10:00
  • Normal Market Close: 12:00

Session-2 from DR Site:

  • Pre-Open: 12:45 - 12:53 (random closure in last minute)
  • Normal Market Open: 13:00
  • T+0 Market Close: 13:30
  • Call Auction Illiquid: 13:00 (2 sessions of 1 hour each)
  • T+0 Trade Modification End: 13:45
  • Auction Market: 14:30 - 15:15
  • Normal Market Close: 15:30
  • Closing Session: 15:40 - 16:00
  • Trade Modification End: 16:15

Re-login Session:

  • Live Re-login: 18:30 - 19:00

Compliance Requirements

  • Members must retain NEAT Adapter settings from Friday, December 19, 2025 to connect to all sessions
  • Members using NNF software must clear outstanding orders from session 1 before trading from BCP site
  • Members must take necessary action per circular NSE/MSD/48662 dated June 18, 2021 to bring systems into consistent state during non-graceful shutdown
  • Members must refer to operational instructions in Annexures 1-4 provided with the circular

Important Dates

  • December 19, 2025: Retain NEAT Adapter settings from this date
  • December 20, 2025: Mock trading session from Primary and DR sites
  • December 20, 2025 (18:30-19:00): Live re-login session
  • December 22, 2025: Normal trading resumes on Monday

Impact Assessment

This is a routine BCP/DR testing exercise with medium operational impact. Members must participate to ensure system readiness and prevent potential login issues. The non-graceful shutdown simulation tests disaster recovery capabilities. No financial obligations or actual trading occurs during the mock session. Technical teams need to be available for the mock and re-login sessions. Colo participants should note different latency patterns during DR operations.

Impact Justification

Routine mock trading session for BCP/DR testing, requires member participation but no market or regulatory impact