Method of Computation

CNX 100 is computed using free float market capitalisation weighted method, wherein the level of the index reflects the total market value of all the stocks in the index relative to a particular base period. The method also takes into account constituent changes in the index and importantly corporate actions such as stock splits, rights, etc without affecting the index value.

Base Date and Value

The CNX 100 Index has a base date of Jan 1, 2003 and a base value of 1000.

Criteria for Selection of Constituent Stocks

CNX 100 index would comprise of the securities, which are constituents of CNX Nifty, and CNX Nifty Junior. In other words this index is a combination of the CNX Nifty and CNX Nifty Junior. Any changes i.e. inclusion and exclusion of securities in CNX Nifty and CNX Nifty Junior would be automatically mirrored in this new index.

From June 26, 2009, CNX 100 is computed using Free Float Market Capitalisation weighted method, wherein the level of index reflects the free float market capitalisation of all stocks in Index.

Index Maintenance plays a crucial role in ensuring stability of the Index as well as in meeting its objective of being a consistent benchmark of the equity markets.

IISL has constituted an Index Policy Committee, which is involved in policy and guidelines for managing the CNX Indices. The Index Maintenance Sub-committee takes all decisions on addition/ deletion of companies in any Index.

The maintenance of the CNX Nifty and the CNX Nifty Junior are synchronised so that the two indices will always be disjoint sets; i.e. a stock will never appear in both indices at the same time. Hence it is always meaningful to pool the CNX Nifty and the CNX Nifty Junior into a composite 100 stock index or portfolio.

The index is reviewed every six months (on half-yearly basis) and a six weeks’ notice is given to the market before making changes to the index set.

Download Details of past changes to CNX 100 Constituents (.xls)