NSE also said that the weightage of the top three constituents will be capped at 19%, 14% and 10%, respectively

Yes Bank, Union Bank of India shares rise up to 3% on inclusion in Bank Nifty from Dec 31

Yes Bank and Union Bank of India Set to Rise Amid Bank Nifty Index Revision

Shares of Yes Bank and Union Bank of India have seen a significant surge, rising up to 3% on December 2, following the announcement by NSE that they will be included in the Bank Nifty index from December 31, 2025.

Key Changes to Bank Nifty Index

The Bank Nifty index will now comprise 14 stocks, up from the current 12.
The weightage of the top three constituents will be capped at 19%, 14%, and 10%, respectively.
The initial proposal had suggested capping the highest weight at 20% and the combined weight of the top three constituents at 45% or less.

Impact on Share Prices

ICICI Bank and HDFC Bank are expected to see outflows of $351 million and $331 million, respectively, which is equivalent to 1.9x and 1.5x of their average daily volume.
Union Bank of India and Yes Bank, on the other hand, are expected to witness inflows of $100 million and $115 million, respectively, which is equivalent to 5.x and 4.9x of their average daily volume.
Other stocks with potential inflows of average daily volume greater than 2x include Federal Bank and AU Small Finance Bank.

Estimated Flows Due to Revision

Nuvama Alternative and Quantitative Research estimates that Yes Bank and Union Bank of India will see inflows of $140 million and $109 million, respectively, due to the revision.
HDFC Bank and ICICI Bank are expected to see outflows worth $322 million and $348 million, respectively, due to their weightage reduction.