The index will track the performance of chemical sector stocks from the Nifty 500. The weight of each stock in the index will be determined by its free-float market capitalisation. To ensure balance, an individual stock’s weight will be capped at 33 per cent, while the combined weight of the top three stocks will be limited to 62 per cent. The base date for this index has been set as April 1, 2005, with a base value of 1,000. The index will undergo a semi-annual reconstitution and a quarterly rebalancing to keep it updated. It is expected to serve as a benchmark for asset managers and will likely be tracked by passive investment funds, such as Exchange Traded Funds (ETFs), index funds, and structured products. The exchange has announced a major change in the expiry days for futures and options (F&O) contracts of several indices.Starting April 3, the expiring days for Bank Nifty, FinNifty, Nifty Midcap Select, and Nifty Next50 will move from the last Thursday of the month to the last Monday of the expirations month.