Description

BSE Index Services changes calculation frequency for BSE Largecap, Midcap, and Smallcap indices from real-time to end-of-day effective January 27, 2026.

Summary

BSE Index Services Private Ltd announces a significant change in the calculation methodology for three major BSE indices. Effective January 27, 2026, BSE Largecap, BSE Midcap, and BSE Smallcap indices will transition from real-time calculation to end-of-day calculation only. This change affects how frequently index values are computed and published throughout the trading day.

Key Points

  • Three BSE indices will change from real-time to end-of-day calculation frequency
  • Affected indices: BSE Largecap, BSE Midcap, and BSE Smallcap
  • Change effective from January 27, 2026
  • Queries can be directed to bseindex@bseindia.com
  • BSE Index Services Private Ltd (formerly Asia Index Pvt. Ltd.) is a wholly owned subsidiary of BSE

Regulatory Changes

No regulatory changes are introduced. This is an operational change in index calculation methodology by BSE Index Services Private Ltd, transitioning the calculation frequency from continuous intraday updates to once-per-day end-of-day calculations.

Compliance Requirements

No specific compliance requirements for market participants. However, entities using these indices for:

  • Investment products tracking these indices
  • Trading strategies based on real-time index movements
  • Risk management systems
  • Portfolio benchmarking

Should update their systems and processes to accommodate the change from real-time to end-of-day index values.

Important Dates

  • Notice Date: January 20, 2026
  • Effective Date: January 27, 2026 - Change in calculation frequency becomes effective

Impact Assessment

Market Impact: Medium - The transition from real-time to end-of-day calculation affects data availability for three significant BSE indices covering different market capitalization segments. Market participants relying on intraday index movements for these specific indices will no longer have access to real-time values.

Operational Impact: Market participants, data vendors, and financial product providers using these indices will need to adjust their systems and expectations. Index funds and ETFs tracking these indices, algorithmic trading strategies, and real-time portfolio monitoring systems may be affected.

Data Availability: Intraday index values will no longer be available for BSE Largecap, Midcap, and Smallcap indices after January 27, 2026. Only end-of-day values will be published.

Note: BSE Sensex and other major indices not mentioned in this circular continue to be calculated in real-time.

Impact Justification

Affects data availability and trading strategies for three major BSE indices, transitioning from real-time to end-of-day calculation, impacting market participants who rely on intraday index values