The story so far: Market regulator, the Securities and Exchange Board of India (SEBI), has taken a well-calibrated step to introduce the Closing Auction Session (CAS) in the equity cash market, aiming for fair valuation, improved depth and statistical reliability of price discovery.

From an econometrics angle, it is an attempt to reduce price noise and improve the information efficiency of Indian equity markets, given that exchange-traded funds (ETFs) and index funds increasingly rely on accurate closing prices to replicate benchmarks.

CAS, introduced on August 3, is a transparent mechanism that relies more on closing auctions than on last traded prices or VWAP (Volume Weighted Average Price), implying that it converts closing price determination from passive averaging into a dynamic demand-supply discovery.

With this move by SEBI, both the National Stock Exchange and the Bombay Stock Exchange have joined major global bourses like NASDAQ, NYSE, London Stock Exchange, Euronext, Hong Kong Stock Exchange, Singapore Stock Exchange, Tokyo Stock Exchange and Australian Securities Exchange.

By making India’s market closing prices more realistic and aligned with international market practices, CAS can potentially improve inflows into Indian equities, especially from institutional investors, even as the impact depends on their chemistry — whether passive (ETFs/index funds) or active funds.

CAS — an official 20-minute auction (3:15 – 3:35 p.m.) that transparently locks in a single closing price — has been gaining popularity since its launch on August 3, initially starting with stocks having futures and options contracts. As SEBI chairman Ruhin Kanta Pandey said, mutual funds’ participation rate in CAS has drastically risen to 25% compared to 5-7% earlier.

In capital markets, the closing price of a security is not merely a number; rather, it is a reference for portfolio valuation, index computation, derivative settlement, mutual fund net asset value calculation and institutional investments; hence, it should reflect the expectations of both sellers and buyers.

The earlier system saw bourses determine the closing price largely through the VWAP of trades in the last 30 minutes of continuous trading, but a few large last-minute trades could disproportionately affect the final average price, creating possibilities of price distortion, especially during large events such as index rebalancing days and derivative expiry days.

It was observed that for NIFTY 50 stocks, the volatility during the last half-hour was higher than the observed volatility for the trading period from 09:15 to 14:30 by 1.8 times and 1.5 times, respectively, on MSCI and FTSE index rebalancing days in 2024.

So, instead of relying only on trades executed before market closure, the system collects buy and sell orders from market participants during the closing auction window. These orders are then matched at an equilibrium price — the price at which the maximum number of shares can be traded.

In contrast to continuous trading, where bids and offers can match instantly, an auction can only result in a trade after it is ended by the exchange. This difference allows more time for supply and demand to find a new equilibrium.

Closing auctions were initially put in place to achieve efficient price discovery, and now they have become increasingly popular as a liquidity event, with volume shares of closing auctions increasing across both Europe and America.

Key differentiator

A key differentiating indicator of CAS is order imbalance — the gap between cumulative buy and sell quantity at different price levels. If the imbalance is low, the discovered price is likely to represent a more stable consensus.

Perceived growth of sophisticated execution algorithms that analyse order imbalance, liquidity patterns and equilibrium prices can potentially make Indian markets evolve towards more institutional-quality trading practices.

Execution efficiency

The auction mechanism allows, especially large investors, to participate anonymously to execute deals at a commonly discovered price, which not only reduces information leakage and improves market confidence but could also reduce the price impact that usually comes with large orders close to market closing time.

Foreign investors managing billions of dollars often prefer markets with predictable closing mechanisms, which CAS can ensure.

Overarching concerns

CAS might face several practical challenges during implementation, especially given that cash market closing prices are determined through CAS, while derivative markets continue to operate separately, creating a temporary gap, particularly around expiry days.

Institutional traders and algorithmic firms may need to rethink strategies, based on traditional VWAP-based closing patterns. Trading models will need to factor in auction imbalances, indicative prices, and real-time order-flows.

Market participants had raised concerns over the sharp difference between index levels before the CAS and the levels recorded after the auction session on the first two trading days, even as SEBI ruled out any foul play.

For many retail investors, the closing price has traditionally meant the last traded price or a value calculated using VWAP. Since this is a new concept, some investors — especially intraday traders and derivatives market participants—may initially find it confusing.

Acknowledging that the industry requires time to grasp the structural reform; SEBI had said “our problem is that there is a lack of understanding because historically algos and other players have based their models on the old mechanism.”

The efficiency of CAS depends on the sufficient order participation. In less liquid securities, limited buy and sell orders may result in a closing price that does not fully represent broader market sentiment.

Equity derivatives continue trading beyond CAS window, temporarily leading to mismatches between spot and futures prices, potentially creating challenges for arbitrage traders.

Case for CAS

India’s passive funds, which have expanded from a relatively small base to multi-crore assets under management, driven by ETFs and index funds, are likely to be the biggest beneficiaries initially.

A well-functioning CAS can make closing price a stronger valuation benchmark by incorporating bid spread, order imbalance, liquidity and investor conviction.

A move towards smarter, transparent and market-driven valuation has already begun, the pace of which hinges on liquidity, participation and regulatory vigilance.

CAS should be evaluated not by short-term volatility but by measurable improvements in market quality — lower tracking errors, reduced closing-price variance, narrower spreads, improved liquidity and stronger price efficiency.

The 50-share NSE Nifty dropped 109.75 points, or 0.46%, to end at 23,946.25. File
| Photo Credit: Getty Images/iStockphoto

Image used for representational purposes only.
| Photo Credit: PTI

The Sensex climbed 347.14 points, or 0.45%, to settle at 77,155.62, and the Nifty rallied 96.55 points, or 0.40%, to end at 24,085.70. File
| Photo Credit: Getty Images/iStockphoto

Stock markets rose for the second straight session with the benchmark Sensex closing higher by 736 points on Monday (June 15, 2026), propelled by a rally in global equities and a sharp decline in crude oil prices after the U.S. and Iran finalised a deal to end their 107-day war.

The 30-share BSE Sensex jumped 736.38 points, or 0.97%, to settle at 76,264.33. During the day, it zoomed 1,293.12 points, or 1.71%, to 76,821.07.

Rising for the second day, the 50-share NSE Nifty surged 231 points, or 0.98%, to end at 23,853.90. During the day, the benchmark rallied 388.5 points, or 1.64%, to 24,011.40. Sensex had rallied 1,695 points or 2.3%, and Nifty soared by 461 points or nearly 2% in the previous session on Friday (June 12, 2026).

The U.S. and Iran finalised a deal to end their 107-day war and open the Strait of Hormuz, the narrow waterway used to ferry one-fifth of the global oil supplies, on Friday (June 12, 2026) after an in-person signing of the agreement in Switzerland.

U.S. President Donald Trump made the announcement on Truth Social on Sunday evening (June 14, 2026), easing pressure on global energy markets, as officials said the peace agreement would be signed on June 19 in Switzerland.

Crude oil prices fell to three-month lows in global markets after the announcement of the U.S.-Iran deal. Global benchmark Brent Crude dropped 5% to trade near $82.90 per barrel.

Among 30 Sensex firms, Trent, InterGlobe Aviation, Bajaj Finserv, UltraTech Cement, Eternal and Maruti were the major winners.

NTPC, ICICI Bank, Asian Paints and Hindustan Unilever were among the laggards.

In Asian markets, South Korea’s Kospi jumped over 5%, while Japan’s Nikkei 225 index climbed nearly 5%. Shanghai’s SSE Composite index and Hong Kong’s Hang Seng index also ended higher.

Markets in Europe were trading in the green. U.S. markets ended in positive territory on Friday (June 12, 2026).

“The easing of geopolitical tensions following the USA-Iran peace agreement is a significant positive for global risk assets. The immediate correction in crude oil prices is particularly encouraging for an import-dependent economy like India, as it helps alleviate inflationary pressures, improves macroeconomic stability, and provides greater policy flexibility,” Rajesh Palviya, Head of Research, Axis Direct, said.

Foreign Institutional Investors (FIIs) offloaded equities worth ₹1,082.18 crore on Friday (June 12, 2026), according to exchange data.

On Friday (June 12, 2026), the Sensex jumped 1,695.40 points, or 2.30%, to settle at 75,527.95. The Nifty ended sharply higher by 461.30 points, or 1.99%, at 23,622.90.

Published – June 15, 2026 04:45 pm IST

Foreign Institutional Investor interest in Indian equities, measured by the net outflows, has been hitting new lows, crossing over ₹2 lakh crore as of May 12, 2026. File
| Photo Credit: Reuters

Stock markets declined for the third consecutive day on Wednesday (December 17, 2025), with the benchmark Sensex closing lower by 120 points at a week’s low due to relentless foreign fund outflows.

The 30-share BSE Sensex edged lower by 120.21 points or 0.14% to settle at 84,559.65. During the day, it dropped 263.88 points or 0.31% to 84,415.98.

The 50-share NSE Nifty declined by 41.55 points or 0.16% to a week’s low of 25,818.55.

Among Sensex firms, Trent fell the most by 1.61%. HDFC Bank dropped by nearly 1%, emerging as a major drag on the index. ICICI Bank, Adani Ports, Bajaj Finserv, Bharat Electronics, Titan and Asian Paints were also among the laggards.

However, State Bank of India rose the most by 1.51%, helping Sensex restrict losses. Infosys, Axis Bank and Maruti were among the gainers.

“Foreign investors are pulling out funds, and emerging markets are struggling, while developed economies remain strong, showing that investors are becoming more cautious about emerging markets,” Vinod Nair, Head of Research, Geojit Investments Limited, said.

“Selling in heavyweight stocks across sectors led to broad-based weakness, while muted cues from global markets further dampened investor sentiment,” Ajit Mishra – SVP, Research, Religare Broking, said.

Analysts said a rebound in the rupee from record low levels offers temporary relief, as global uncertainty and sustained foreign selling keep upside potential limited.

The rupee rebounded sharply by over 1% in the early session to trade at the 89 level against the U.S. dollar briefly on heavy dollar selling by banks. The rupee later pared gains to close at 90.38, up by 55 points over the last record closing low of 90.93.

Foreign Institutional Investors (FIIs) offloaded equities worth ₹2,381.92 crore on Tuesday (December 16), while Domestic Institutional Investors (DIIs) bought stocks worth ₹1,077.48 crore, according to exchange data.

The BSE smallcap gauge declined 0.85% and midcap index dipped by 0.53%.

Among sectoral indices, capital goods declined by 0.96%, realty (0.81%), consumer durables, industrials (0.76%), services (0.64%).

BSE Energy, IT, metal, oil & gas, tech and BSE Focused IT were the gainers.

A total of 2,694 stocks declined while 1,475 advanced and 159 remained unchanged on the BSE.

In Asian markets, South Korea’s Kospi, Japan’s Nikkei 225 index, Shanghai’s SSE Composite index, and Hong Kong’s Hang Seng index ended in positive territory.

European markets were trading higher. U.S. markets ended mostly lower on Tuesday (December 16).

Brent crude, the global oil benchmark, jumped 2.12% to $60.17 per barrel.

On Tuesday (December 16), the Sensex tanked 533.50 points or 0.63% to settle at 84,679.86. The Nifty dropped 167.20 points or 0.64% to 25,860.10.

Published – December 17, 2025 05:09 pm IST

The 30-share BSE Sensex dipped 54.30 points, or 0.06%, to 85,213.36. File
| Photo Credit: The Hindu

For the second day, the BSE index sensex and the NSE index nifty, surged
| Photo Credit: PTI

Benchmark stock indices Sensex and Nifty rebounded on Thursday (December 11, 2025), cutting short a three-day falling streak following buying in auto and metal stocks and a rate cut by the U.S. Federal Reserve.

Rebounding from its early lows, the 30-share Bombay Stock Exchange (BSE) index, Sensex, climbed 426.86 points or 0.51%, to settle at 84,818.13. During the day, it hit a high of 84,906.93 and a low of 84,150.19.

The 50-share National Stock Exchange (NSE) index, Nifty, appreciated by 140.55 points, or 0.55%, to close at 25,898.55. Following initial volatility, the Nifty gradually moved higher and closed near the day’s peak of 25,922.80 as most sectors advanced.

Among the Sensex constituents, Eternal, Tata Steel, Kotak Mahindra Bank, UltraTech Cement, Maruti Suzuki India, Sun Pharmaceuticals, Tech Mahindra, HDFC Bank, Tata Motors Passenger Vehicles, Infosys, Trent, Mahindra and Mahindra, Reliance Industries and HCL Technologies were the gainers.

However, Asian Paints, Bharti Airtel, Bajaj Finance, PowerGrid, Axis Bank, ICICI Bank and Titan were among the laggards.

“Domestic markets rebounded broadly following the Fed’s expected 25 basis points rate cut amid high U.S. inflation. The decline in U.S. 10-year yields indicates a moderation in future Foreign Institutional Investor (FII) outflows, which bolstered sentiment,” Vinod Nair, head of research, Geojit Investments Ltd, said.

Mr. Nair added that the auto sector excelled due to anticipated stronger demand, while IT gained traction on the prospect of increased spending. Conversely, other Asian markets experienced selling pressure over concerns about AI-driven valuations and rising Japanese yields, which negatively impacted overall domestic sentiment.

Ajit Mishra – senior vice president, research, Religare Broking Ltd said buying across IT, auto, metals, realty and banking helped offset recent weakness, supported by a decline in India Volatility Index (VIX). Steady domestic sentiment was reinforced by robust equity inflows of ₹29,894 crore in November. However, continued weakness in the rupee capped the momentum he added.

In Asian markets, Japan’s Nikkei 225 benchmark, Shanghai Stock Exchange Composite, South Korea’s Composite Stock Price Index (KOSPI) and Hong Kong’s Hang Seng settled lower.

European markets are trading higher. Wall Street settled higher in overnight deals on Wednesday (December 10, 2025).

Meanwhile, Foreign Institutional Investors (FIIs) remained the net sellers of equities worth ₹1,651.06 crore on Wednesday (December 10, 2025) while Domestic Institutional Investors (DIIs) bought stocks worth ₹3,752.31 crore, according to the exchange data.

Brent crude, the global oil benchmark, declined 1.22% to $61.45 per barrel.

On Wednesday (December 10, 2025), the 30-share BSE index, Sensex, dropped by 275.01 points to settle at 84,391.27, while the broader NSE index, Nifty, fell by 81.65 points to close at a month’s low of 25,758.

Published – December 11, 2025 04:45 pm IST