NSE: Historic ₹39,718 crore single-day turnover in Closing Auction Session - Massive surge, MSCI index review and more

The National Stock Exchange of India (NSE) recorded a historic ₹39,718 crore turnover in its Closing Auction Session (CAS) on Monday, 31 August, accounting for 22% of the exchange's total cash market turnover, as the mechanism faced its first major test during the MSCI August 2026 Index Review.

The turnover was around 42 times higher than that recorded in the previous trading session, with more than 98,000 unique investors participating in the closing auction. NSE also commanded a 99.9% market share in the CAS during the session.

The sharp surge in activity came as the MSCI August 2026 Index Review took effect at the close of trading on August 31. The session marked the first major index rebalancing event since the closing auction session was introduced in Indian capital markets earlier this month.

Index review and rebalancing events typically result in heavy trading towards the end of the session as index funds, exchange-traded funds (ETFs), and other passive investors realign their portfolios to reflect changes in benchmark indices.

NSE said the strong participation and record turnover demonstrated that index funds and passive investors used the CAS mechanism to execute their rebalancing trades.

MSCI review drives massive surge in closing auction activity

The MSCI index review provided the first major test for the newly introduced closing price discovery mechanism, with the ₹39,718 crore turnover underlining the significant rise in demand for the session during large portfolio rebalancing events.

"The successful completion of the first month of the Closing Auction Session marks an important milestone for the Indian capital markets, and the confidence shown by the market on the first index rebalancing day after CAS went live is a strong endorsement of the mechanism," ANI reported, citing Sriram Krishnan, Chief Business Development Officer at NSE.

Krishnan was quoted in the report as saying that the exchange was encouraged by the participation of market participants, particularly index funds and passive investors, during the rebalancing session.

CAS finishes one month

Monday also marked the completion of one month since the closing auction session was introduced in the Indian capital markets. During its first month, NSE recorded cumulative CAS turnover of around ₹63,000 crore and commanded a market share of 98.2%.

The CAS was implemented from August 3 following the Securities and Exchange Board of India's decision to introduce the mechanism for stocks in the cash segment on which derivative contracts are available.

Under the call auction mechanism, buy and sell orders at the close of the market are aggregated into a single price discovery process to determine the closing price of eligible stocks. Unlike relying solely on trades during continuous market hours, the mechanism brings closing buy and sell interest together to improve transparency, integrity, and fairness in price discovery.

NSE said the introduction of CAS brings Indian capital markets closer to global best practices for determining closing prices, while Monday's record turnover highlighted its potential role during major index rebalancing events.

(With inputs from ANI and PTI)

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