New Indian closing auction mechanism drives wild stock swings

Zerodha co-founder Nithin Kamath has weighed in on the volatility plaguing Indian equities under the new closing auction framework. According to reports, Kamath stated that the sharp swings observed in the Closing Auction Session (CAS) reflect structural vulnerabilities in Indian markets rather than inherent defects in the mechanism itself. The new 20-minute auction system, which replaced the earlier VWAP-based close, has generated unpredictable late-day price movements. These swings have resulted in losses for options traders and algorithmic trading desks, prompting industry participants to call for either modifications to the system or its complete rollback.

The introduction of the CAS represents a significant shift in how Indian markets determine closing prices. The structural distortions now evident suggest deeper issues within market microstructure and liquidity distribution across trading sessions. For traders and investors, such volatility creates both risks and opportunities—particularly impacting derivatives markets where closing prices serve as crucial settlement references. Options traders face heightened challenges as gamma exposure intensifies during the auction window, while algo desks struggle with execution unpredictability. The debate reflects broader tensions in market design: regulators seeking to improve price discovery mechanisms versus market participants concerned about operational stability. Indian market authorities will likely need to address these structural concerns to restore confidence in the closing mechanism, whether through system refinements or alternative approaches.

Source: Markets-Economic Times