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Sensex puts surge as closing auction sees 2,100-point swing
BusinessLine 1 hr ago·3 Sept 2026, 3:57 pm
The closing auction mechanism, known as the Closing Auction Session (CAS), is currently driving significant volatility in the Indian market. This system, which determines the final price for the day, has recently seen a massive 2,100-point swing in the Sensex. Such extreme fluctuations are unusual and indicate that the auction is not functioning as a stabilizing force. Instead, it is becoming a tool for large traders to influence the day's final price.
This divergence between the closing auction price and the previous day's close is concerning for investors. It suggests that the market lacks sufficient participation from smaller traders to set a fair price. When a few large players dominate the auction, it can distort the true value of stocks, making it difficult for retail investors to trust the closing price as a reliable indicator of market sentiment.
Investors should pay close attention to the volume and participation levels during the final 15 minutes of trading. A healthy market requires broad participation to ensure a balanced price discovery process. If the auction continues to see such high volatility, it may prompt regulators to review the rules to ensure fair trading practices for all participants.
Excerpt from BusinessLine
Sensex put options spiked sharply on expiry day after the index fell over 2,000 points in three minutes during the closing auction session (CAS) on Thursday, reviving worries about low liquidity in auction. The Sensex eventually ended the day 417.49 points, or 0.55 per cent, lower at 76,152.86. The Nifty closed 41…Read the original at BusinessLine
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- Category: Stocks.
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