# NSE Trading Rules Overhaul

> NSE shortens CAS to 10 minutes, revises F&O expiry hours from Dec 7.
- Title: NSE Trading Rules Overhaul · mint | Shortify
- Summary: NSE shortens CAS to 10 minutes, revises F&O expiry hours from Dec 7. NSE reduces Closing Auction Session to 10 minutes and extends derivatives trading hours…
- Keywords: nse, closing auction session, f&o expiry, trading hours, december 7, equity cash segment, derivatives contracts, mint
- Source: mint — https://livemint.com/market/stock-market-news/nse-overhauls-key-trading-rules-closing-auction-session-f-o-expiry-trading-hours-revised-what-changes-from-dec-7-11794047384672.html
- Author: Sharmila Bhadoria
- Published: 2026-11-07T10:35:22+00:00
- Read time: 1 min
- Topics: nse, closing auction session, f&o expiry, trading hours, december 7, equity cash segment, derivatives contracts, money, business
## Key Changes Announced
The NSE will overhaul Closing Auction Session (CAS) in equity cash segment and trading modalities in derivatives from December 7.
## CAS Duration Revised
CAS duration shortened to 10 minutes with revised closing price discovery methodology.
## Derivatives Trading Hours
Extension of derivatives trading hours to 3:45 pm effective December 7.
## CAS Timing Details
CAS runs from 3:30 pm to 3:45 pm with specific order entry and matching periods.
## CAS Methodology
Reference price determined by volume-weighted average price of trades between 3:15 pm and 3:30 pm.
## Key takeaway

NSE reduces Closing Auction Session to 10 minutes and extends derivatives trading hours to 3:45 pm starting December 7.