The National Stock Exchange (NSE) has extended the normal trading hours for the equity derivatives or Futures & Options (F&O) segment by 10 minutes, effective Monday, August 3. From now on, F&O trading will remain open until 3:40 PM, instead of the earlier closing time of 3:30 PM.

The move has been introduced to align the derivatives market with the Closing Auction Session (CAS) that is being implemented in the cash segment. The change is aimed at improving price discovery, ensuring smoother coordination between cash and derivatives markets, and bringing Indian market practices closer to global standards.

Why Has NSE Extended F&O Trading Hours?

According to an NSE circular, the extension is part of the rollout of the new Closing Auction Session in the cash market. Synchronising the closing time of equity derivatives with the auction-based closing process in the cash segment is expected to enhance market efficiency and reduce pricing discrepancies.

The exchange clarified that there will be no changes to other trading sessions, including the pre-open session or the trade modification window.

What is the Closing Auction Session (CAS)?

The Closing Auction Session is a dedicated trading window conducted at the end of the trading day. During this period, market participants place buy and sell orders to determine a single, fair closing price for eligible securities.

The auction mechanism is designed to improve transparency and provide a more accurate closing price, particularly for stocks that have derivative contracts.

The same price bands and pre-trade risk management rules applicable to the cash market's Closing Auction Session will also apply to the derivatives segment.

Changes in Closing Price Calculation

While the methodology for calculating the closing price of derivatives contracts remains unchanged, the time window used for the calculation has been revised.

The Volume Weighted Average Price (VWAP) used to determine the closing price will now be calculated using trades executed between 3:10 PM and 3:40 PM, reflecting the extended market hours.

Automatic Cancellation of Certain Orders

NSE also said that if the operating price range for stock futures is reset after the Closing Auction Session begins in the cash market, the exchange will issue a notification.

Any pending orders lying outside the revised price range will be automatically cancelled, in line with existing exchange rules.

Brokers Asked to Update Systems

The exchange has advised brokers to update their trading applications and contract files before the revised timings take effect. Functional changes related to the new system will also be available for testing during upcoming mock trading sessions to ensure a smooth transition.

How the Closing Auction Session Will Work

The Closing Auction Session will be conducted every trading day from 3:15 PM to 3:35 PM, following a structured process:

• 3:15 PM – 3:20 PM: Transition phase from continuous trading to the auction session. The reference price will be calculated based on the VWAP of trades executed between 3:00 PM and 3:15 PM.

• 3:20 PM – 3:25 PM: Both market orders and limit orders can be placed.

• 3:25 PM – 3:30 PM: Only limit orders will be accepted. Market orders cannot be modified or cancelled during this phase. Order entry will close randomly between 3:28 PM and 3:30 PM.

SEBI's Phased Implementation

The Closing Auction Session is being introduced in phases under SEBI guidelines issued on January 16. In the first phase, only stocks with listed derivatives contracts will have their closing prices determined through the auction mechanism.

For all other securities in the cash market, the closing price will continue to be calculated using the VWAP of trades executed during the final 30 minutes of regular trading.

What is the F&O Market?

The Futures & Options (F&O) market is a segment of the stock market where investors trade derivative contracts whose value is linked to an underlying asset such as shares or indices. These contracts are commonly used for hedging risks as well as speculative trading.

What is VWAP?

Volume Weighted Average Price (VWAP) is the average trading price of a stock calculated after considering both its price and the volume of shares traded. It is widely used by traders and institutions to assess the average price at which a stock has traded during a specific period.