The clarification comes in the wake of Nifty 50’s official closing value as it jumped nearly 200 points on Monday after continuous trading had ended, surprising market participants on the first day of the Closing Auction Session (CAS) for stocks in the futures and options (F&O) segment.
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REUTERS/FRANCIS MASCARENHAS
The National Stock Exchange, in an V-hour clarification, said that Closing Auction Session was implemented under the guidance of SEBI as it promotes transparency and fair and robust price discovery.The clarification comes in the wake of Nifty 50’s official closing value as it jumped nearly 200 points on Monday after continuous trading had ended, surprising market participants on the first day of the Closing Auction Session (CAS) for stocks in the futures and options (F&O) segment. Major indices and several stocks witnessed an unusual divergence between cash and futures prices that triggered confusion among market participants.The Nifty 50 closed at 24,774.30, up 390.70 points or 1.6 per cent, after jumping nearly 200 points after the closing auction alone. Heavyweights ICICI Bank, HDFC Bank, Reliance Industries, Infosys, Bharti Airtel, and Bajaj Finance were among the top traded stocks on NSE.The index graph does not show a sudden change at 3:30 pm during the Closing Auction Session (CAS). “This is because there are no actual trades between 3:15 pm and 3:30 pm, so the index remains unchanged and is based only on completed trades. During this period, orders are collected, modified, cancelled, and matched. Meanwhile, the Exchange website displays indicative index values next to the “Get Quote” section. These values are updated continuously based on the equilibrium prices calculated during the CAS, even though no trades are taking place,” according to a statement from the NSE.Besides, both stock exchanges maintain separate order books during the Closing Auction Session (CAS), just like they do during normal trading. Because the buy and sell orders are different on each exchange, the closing prices of individual stocks can also differ. Since an index is calculated using the prices of its constituent stocks, the index values on the two exchanges may also be different.“Both the Exchanges have separate order books for CAS session similar to the continuous trading session and hence, the prices of the individual stocks are also different. As the index is calculated based on the prices determined of the individual stocks, the index values can also be different. In a study of open prices of scrips based on pre open call auction session during the period 2014 to 2024, it was found that there were more than 8.5 lac scrip days where the open price difference was more than 2%,” NSE said“Today was the first day of CAS implementation, however, on the first day itself 515 trading members participated and they placed orders for 56773 unique PANs. It was more than todays Pre-open call auction session where 403 trading members participated who placed orders for 42822 unique PANs. It may be noted that Pre open session has been implemented more than a decade ago. So given the first day, the participation levels were very good. This is expected to mature and increase with time,” it further said in a press release.More Like ThisPublished on August 4, 2026
