has finalised major revisions to the methodology of the Nifty Bank Index, marking one of the most significant structural changes to the benchmark in recent years.
The revised weightage rules for the Nifty Bank and Nifty Financial Services, announced on Monday, align with SEBI’s norms on weight concentration.
According to the exchange statement, the Nifty Bank index will expand to a fixed 14 constituents, up from the previous maximum of 12. The changes were introduced in line with NSE Indices’ updated methodology and recent regulatory requirements.
Under the revised framework, constituent selection will be driven primarily by six-month average free-float market capitalization, with inclusion restricted to stocks eligible for trading in the NSE’s derivatives segment. If fewer than 14 such stocks meet the criteria, the remaining slots will be filled from the broader eligible universe based on free-float rankings.
One of the most notable adjustments is the introduction of fixed weight caps for the top three constituents—19 per cent for the largest, 14 per cent for the second, and 10 per cent for the third. This brings the combined cap for the top three banks to 43 per cent, a move intended to improve diversification and reduce concentration risk, Nuvama Alternative & Quantitative Research report observed. Weights of all other constituents will be tiered beneath the top three in descending order.
Non-F&0 stocks will see a 4.5 per cent individual cap and 10 per cent cumulative ceiling.
The revised index will be implemented in four phased tranches: December 2025, January 2026, February 2026, and March 2026. The first tranche becomes effective December 31, following an adjustment on December 30.
The reshuffle brings two new entrants into the index: and . Both will be added at once, while the gradual reweighting of the top three banks will occur across the scheduled quarterly reviews.
Both the newly added stocks and the existing members are likely to see slight weight changes in the all four tranches, the report read.
Nuvama’s estimates indicate that the multi-stage recalibration will trigger steady adjustments in stock weights.
Projections included in the research show that heavyweights such as HDFC Bank and ICICI Bank will see material weight reductions through the four-month transition, while several mid-tier banks—including Bank of Baroda, Punjab National Bank, Canara Bank, Federal Bank, and AU Small Finance Bank—are expected to gain weight. The newly added Yes Bank and Union Bank of India will also see incremental increases as the cap-based normalisation progresses.
Nuvama’s flow analysis suggests significant cumulative outflows for the largest constituents and sizeable inflows for the new additions and rising mid-tier names.