Description

NSE introduces additional indicator in order log reports for Pre-Open session in F&O segment effective December 08, 2025.

Summary

NSE has announced that additional indicators will be provided in order log reports to identify Pre-Open session orders in the Equity Derivatives (F&O) segment. This update is effective from December 08, 2025, and is a continuation of the Pre-Open Session introduction announced in circular NSE/FAOP/71092 dated November 03, 2025. The changes will add a “Book Type” field with value “8 - Pre-Open” to identify orders placed during the pre-open session.

Key Points

  • Additional indicator to be added to order log reports from December 08, 2025
  • New “Book Type” field will identify Pre-Open session orders with value “8 - Pre-Open”
  • Changes apply to Order.txt file (field numbers 9 and 10) and Split Order Log file (field number 5)
  • No change in file format; Pre-Open session data will be integrated into existing files
  • Order.txt file available through NEAT screen (online backup)
  • Split Order Log file (FO_ORD_LOG_<TM_ID>.CSV.gz) available on extranet server at \faoftp\F folder

Regulatory Changes

This is a technical enhancement to existing reporting infrastructure. The Pre-Open session functionality was previously introduced via circular NSE/FAOP/71092 dated November 03, 2025. This update adds tracking and identification capabilities for Pre-Open orders in the order log reports.

Compliance Requirements

  • Members should update their systems to recognize and process the new “Book Type” indicator (value 8) for Pre-Open session orders
  • Members need to ensure their order processing and reconciliation systems can handle the additional data field
  • No changes to file formats, so existing parsers should continue to work with the additional data values

Important Dates

  • Circular Date: December 02, 2025
  • Implementation Date: December 08, 2025 - Additional indicator becomes available in order log reports

Impact Assessment

Operational Impact: Medium - Members will need to update their back-office systems and reporting tools to recognize and potentially filter/process Pre-Open session orders separately. The impact is limited as file formats remain unchanged, minimizing integration work.

Market Impact: Low - This is a reporting enhancement that provides better visibility and tracking of Pre-Open session activity. It does not affect trading mechanisms or market structure.

Technical Impact: Members using automated order processing systems should validate that the new Book Type values are handled correctly in their reconciliation and reporting workflows.

Impact Justification

Technical update to order log reports for pre-open session tracking; affects members' reporting systems but does not change trading rules or member obligations significantly.