The Securities and Exchange Board of India (SEBI) has rolled out a new closing auction session (CAS), expected to boost Indian equities market infrastructure.
The new session – which went live on 3 August 2026 – is expected to enhance price discovery and curb late-day price manipulation in these markets, with the aim of better aligning the Indian market more closely with established international best practice. 
Specifically, the offering moves India’s two main stock markets – National Stock Exchange (NSE) and Bombay Stock Exchange (BSE) – from a calculated closing price structure to an executable auction price, based off concentrated market demand.
Through this shift, the exchanges will no longer depend on a 30-minute VWAP for F&O eligible stocks between 3pm and 3.30pm.
Instead, the new CAS run a 20-minute auction phase for the buying and selling of bids, following which a single equilibrium matching price is calculated, and the official closing price is finalised and published.
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SEBI initially announced consultations around introducing a new CAS for Indian equity markets in December 2024 and confirmed the new offering would be implemented into the equity cash segment of the stock exchanges in January 2026.
Following the announcement, Quorum 15 was confirmed as one of the industry bodies involved as ‘an active supporter and contributor’ to the development of the reform, labelling it an ‘important structural shift in India’s equities markets’.
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Speaking about the news, Mike Burton, Q15 founder, said that CAS’ introduction should be “viewed as the beginning of a journey rather than the final destination” and “experience from other markets shows that auction participation and liquidity build progressively over time as investors, intermediaries and technology providers adapt processes and behaviours.”