Markets regulator Sebi has introduced a new framework to classify stock market benchmarks as “significant indices” if mutual fund schemes tracking them have a daily average cumulative assets under management (AUM) of more than Rs 20,000 crore for each of the preceding six months, PTI reported.The move is aimed at strengthening transparency, governance and accountability in the index ecosystem.“It is specified that a Benchmark or Index (including index of indices) based on listed securities shall be considered as ‘significant Indices’, if the daily average cumulative AUM tracking the Benchmark or Index across schemes of Mutual Fund(s) exceeds Rs 20,000 crore for each of the past six months, ending on June 30 and December 31 each year,” Sebi said in a circular.The regulator said the threshold will be reviewed on a half-yearly basis, and once classified as significant, an index will continue in that category unless its tracked AUM falls below the threshold for three consecutive years.The framework follows the introduction of the Sebi (Index Providers) Regulations, 2024, which govern entities administering such indices.Sebi also released an initial list of indices that qualify under the new norms. These include major benchmarks such as the BSE Sensex, Nifty 50, Nifty 500 and BSE 500, along with several sectoral, debt and hybrid indices managed by NSE Indices Ltd, BSE Index Services Pvt Ltd and CRISIL.Under the new rules, index providers offering significant indices must apply for Sebi registration within six months.However, indices already notified or authorised as benchmarks by the Reserve Bank of India under relevant RBI provisions have been exempted from this requirement.Existing index providers can continue operations during the transition phase if they file registration applications within the stipulated timeline.Sebi also said entities already registered in another category with the regulator but engaged in index-related activities will have to create a separate legal entity within two years to undertake index provider operations.The regulator clarified that grievance redressal mechanisms under the new regulations will apply only to significant indices administered by Sebi-registered index providers.