Securities and Exchange Board of India has announced a major update to the Closing Auction Session framework to improve transparency and efficiency in market operations. The revised timings will see the CAS run from 3:30 pm to 3:40 pm, while derivatives trading will continue till 3:45 pm.
According to SEBI, the new CAS changes will come into effect from December 7, 2026. The regulator has also introduced new rules for unexecuted orders. Eligible limit orders that remain pending during continuous trading will automatically move to the CAS window. Similarly, unexecuted iceberg orders will transition into fully disclosed limit orders unless traders choose to opt out.
The transition of order handling will become effective from February 8, 2027. SEBI expects these changes to improve closing price accuracy by nearly 15% and reduce volatility in the final minutes of trading.
Market experts believe the revised framework will help investors achieve fairer closing prices and better alignment between cash and derivatives markets. The move is part of SEBI’s broader effort to modernise trading systems and strengthen investor confidence.
