NSE Extends F&O Trading Till 3:40 PM Under New CAS Rules

NSE has announced major changes for the Equity Derivatives segment due to the introduction of the Closing Auction Session (CAS) in the cash market. The new framework will come into effect from August 3, 2026.

Equity derivatives trading will now continue until 3:40 PM instead of 3:30 PM. The change applies to all stock and index futures and options contracts. Pre open and market opening timings remain unchanged.

A new CAS window will operate from 3:20 PM to 3:30 PM, following a transition period from 3:15 PM to 3:20 PM for reference price calculation. No fresh orders can be entered during the transition period.

For stock futures, NSE will apply a fixed price band of ±3% based on a reference price calculated after 3:15 PM. Dynamic price band revisions will not be allowed during the CAS period.

Only Market on Close (MOC) and Limit on Close (LOC) orders will be accepted in CAS. Market orders cannot be modified or cancelled between 3:25 PM and 3:30 PM, while limit orders can be modified under specified conditions.

CAS will initially apply only to cash market stocks that have derivatives contracts. Non F&O stocks will continue normal trading until 3:30 PM. NSE will also publish indicative prices, buy and sell quantities, imbalance data and index values during the auction process.