Archive · 6 Aug 2026
Nifty Closing Auction Gap Narrows as Markets Adapt
The stock market has a new way to decide the final price of stocks at the end of the day.
It is called the Closing Auction Session, or CAS.
Before, the last 30 minutes of trading decided the closing price.
Now, all buy and sell orders are gathered together at the end of the day.
The stock gets one price where the most shares can be traded.
Big stock markets in the US and UK already do this.
At first, the new price was very different from the old closing price.
The difference was 184 points on the first day.
Now the difference is only 8 points, so people are getting used to it.
Experts say this makes prices fairer and harder to trick.
The gap between Nifty's pre-CAS and post-CAS closing prices narrowed to just 8 points on Thursday, with Nifty settling at 24,628 at 3:15 pm and 24,636 after the Closing Auction Session.
The difference has shrunk steadily from 184 points on August 3 and 155 points on August 4 to 55 points on Wednesday.
Exchanges launched the Closing Auction Session (CAS) on Monday, pooling end-of-day buy and sell orders to set a single closing price at which the maximum number of shares can trade.
Experts say CAS makes end-of-day prices more transparent and harder to influence with last-minute trades, while reducing tracking error for index funds and ETFs.
Gibin John of Geojit Investments said CAS is expected to improve price discovery and may slightly reduce arbitrage opportunities, with fund managers adapting to new conditions.
- Who
- The National Stock Exchange (NSE), which runs the Nifty index, along with market participants including index funds and ETF investors; experts Shweta Rajani of Anand Rathi Wealth and Gibin John of Geojit Investments commented on the change.
- What
- The gap between Nifty's pre-Closing Auction Session (CAS) closing price and its post-CAS closing price has narrowed to just 8 points as markets adapt to the new closing price mechanism.
- When
- August 2026 - CAS was implemented on Monday, August 3, with data reported through Thursday, August 6.
- Where
- Indian stock exchanges, notably the NSE's Nifty index.
- Why
- CAS pools end-of-day buy and sell orders to determine a single closing price where the most shares can trade, making end-of-day prices more transparent and harder to influence with last-minute trades.
- Index
- Nifty
- CAS implemented
- Monday, August 3, 2026
- Gap on Aug 3 (first CAS day)
- 184 points
- Gap on Aug 4
- 155 points
- Gap on Wednesday
- 55 points
- Gap on Thursday
- 8 points
- Nifty close at 3:15 pm Thursday
- 24,628 points
- Nifty post-CAS close Thursday
- 24,636 points