SEBI chief finds no manipulation in closing auction session, eyes wider participation
Synopsis
SEBI chief Tuhin Kanta Pandey has cleared the newly launched closing auction session of any manipulation — but the regulator's bigger challenge is getting brokers and investors to actually use it. With mutual fund NAVs and index values riding on the mechanism's integrity, how participation grows over the coming weeks will be the real test of this global-standard reform.
Key Takeaways
SEBI Chairman Tuhin Kanta Pandey on 12 August said no evidence of manipulation has been found in the new closing auction session (CAS) .
The CAS is a dedicated 20-minute session in which buy and sell orders are matched to set a stock's official closing price.
It replaces the earlier method of using a weighted average of trades from the final 30 minutes of the regular session.
Closing prices from CAS directly influence mutual fund NAVs , index calculations, and passive investment benchmarks.
Markets including Japan (2024), Hong Kong , the US , Germany , and Australia already use auction-based closing price discovery.
SEBI is in active consultation with brokers and intermediaries to increase participation in the new system.
Securities and Exchange Board of India (SEBI) Chairman Tuhin Kanta Pandey on Wednesday, 12 August said the regulator has found no evidence of manipulation in the newly introduced closing auction session (CAS), pushing back against concerns raised by some market participants over the mechanism. Pandey made the remarks at an event in Mumbai, calling the CAS a landmark microstructure reform.
What Pandey Said
Pandey defended the new system as a necessary step toward aligning Indian markets with global best practices. 'CAS is a very big microstructure reform, and we are actually behind it. Many of our global counterparts have already done it. Japan did it in 2024. Hong Kong has done it. It is in the US, in Germany, in Europe, and in Australia. So, this is a very important thing. Whatever index you do, for passive investing and NAV values of mutual funds, you need a price,' he said.
On the question of participation, Pandey acknowledged that broader engagement remains a work in progress. 'Now, we need to increase participation. More and more people should understand it. Brokers, many brokers have indicated prices. So basically, the issue is that participation should increase in CAS. CAS is a transparent market; its pricing is always visible, what is happening inside it is visible, and finally, it makes a price. So, SEBI is talking to different people, and we are understanding and considering everyone's input,' he added.
How the Closing Auction Session Works
The closing auction session, introduced by stock exchanges last week, runs for a dedicated 20-minute window after the regular trading session. During this period, buy and sell orders are collected and matched to determine a stock's official closing price — set at the level where the maximum executable volume can be transacted.
This replaces the earlier methodology, under which closing prices were derived from the weighted average of trades executed in the final 30 minutes of the regular session. Regulators and exchanges have said the revised framework is designed to deliver a fairer, more transparent, and more efficient price discovery process, particularly for large institutional orders.
Why It Matters
The shift carries significant downstream implications. Closing prices determined through the CAS feed directly into index calculations, mutual fund net asset values (NAVs), and passive investment benchmarks — making the integrity of the mechanism a systemic concern. This is precisely why SEBI has been monitoring the new system closely since its rollout.
Notably, India joins a long list of major markets — including Japan, Hong Kong, the United States, Germany, and Australia — that already rely on auction-based closing price discovery. Japan's transition to a similar system as recently as 2024 underscores that this is an ongoing global convergence, not an outlier move.
SEBI's Next Steps
SEBI said it is actively reviewing stakeholder feedback and remains open to measures that could deepen participation in the CAS. The regulator is engaged in consultations with brokers and other market intermediaries to address operational concerns. No timeline for further structural changes has been announced.
Point of View
But it sidesteps the harder question: if participation in the CAS remains thin, the mechanism's price discovery value is inherently limited — regardless of whether manipulation occurred. A closing price formed on low volume can be just as distorted as one formed on a manipulated one. SEBI's own framing — that 'participation should increase' — implicitly concedes this. The regulator's credibility on this reform will ultimately rest not on the absence of manipulation, but on whether the CAS produces closing prices that institutional and retail participants trust enough to trade around.
NationPress
12 Aug 2026
Frequently Asked Questions
What is the closing auction session (CAS) introduced by Indian stock exchanges?
The closing auction session is a dedicated 20-minute window introduced by Indian stock exchanges in which buy and sell orders are collected and matched to determine a stock's official closing price at the level of maximum executable volume. It replaces the earlier weighted-average method based on the final 30 minutes of regular trading.
Why did SEBI introduce the closing auction session?
SEBI introduced the CAS to provide a fairer, more transparent, and more efficient closing price discovery process, particularly for large institutional orders. The mechanism also aligns India with global market practices followed in Japan, Hong Kong, the US, Germany, and Australia.
Has SEBI found any manipulation in the new closing auction session?
No. SEBI Chairman Tuhin Kanta Pandey stated on 12 August that the regulator has found no evidence of manipulation in the CAS since its introduction last week. SEBI is, however, monitoring participation levels and gathering stakeholder feedback.
Why does the closing auction session matter for mutual fund investors?
The closing prices determined through the CAS feed directly into mutual fund net asset values (NAVs) and index calculations used for passive investing. Any distortion in closing prices — through low participation or manipulation — would affect the value at which mutual fund units are priced.
What is SEBI doing to increase participation in the closing auction session?
SEBI is actively consulting with brokers and market intermediaries to understand concerns and explore measures to broaden participation. Chairman Pandey said the regulator is open to all stakeholder input, though no specific timeline or structural changes have been announced yet.
