Stock Market Timings Change From 3 August 2026: New CAS Timings Explained

Indian stock market timings are changing from 3 August 2026. SEBI is introducing a new Closing Auction Session, or CAS, for stocks that are available for trading in the futures and options segment. Trading hours for equity futures and options will also be extended by 10 minutes.

The market will continue to open at 9:15 AM. However, the closing process will now depend on whether you are trading:

• An F&O-eligible stock
• A stock without F&O contracts
• Equity futures or options
• Intraday positions

Here is what is changing and how it may affect your orders.

What Is the Closing Auction Session?

The Closing Auction Session is a separate session conducted near the end of the trading day to determine a stock’s official closing price.

At present, a stock’s closing price is generally calculated using its volume-weighted average price during the final 30 minutes of regular trading.

Under CAS, the exchange will instead collect buy and sell orders during an auction. It will then determine a single price at which the maximum possible quantity of shares can be traded.

In the first phase, CAS will apply only to stocks with futures and options contracts available on both NSE and BSE.

Regular trading in these stocks will stop at 3:15 PM. They will then enter the closing auction process.

Stocks that are not covered under CAS will continue trading normally until 3:30 PM.

Why Is SEBI Introducing CAS?

A stock’s closing price is used for several important calculations, including:

• Index values
• Futures and options settlement
• Mutual fund net asset values
• Investor portfolio valuation
• Passive fund performance

Large orders placed during the final few minutes of regular trading can sometimes have a disproportionate impact on the closing price.

CAS is designed to reduce this risk. Instead of allowing trades to execute continuously until the market closes, the exchange will pool orders from multiple buyers and sellers. These orders will then be matched at a common equilibrium price.

This can improve closing-price discovery and make it more difficult for a small number of last-minute trades to influence the final price.

It may also help index funds and other passive funds execute orders closer to the official closing price, potentially reducing tracking differences.

New Stock Market Timings From 3 August 2026

The revised closing time will depend on what you are trading.

1. F&O-Eligible Stocks

Continuous trading in stocks covered under CAS will take place from 9:15 AM to 3:15 PM. After 3:15 PM, these stocks will enter the Closing Auction Session.

Their official closing price will be determined through the auction instead of regular continuous trading.

2. Stocks Without F&O Contracts

There is no change in regular trading hours for stocks that are not covered under CAS. These stocks will continue trading from 9:15 AM to 3:30 PM Their closing price will continue to be calculated using the existing volume-weighted average price method.

3. Equity Futures and Options

Trading hours for stock and index futures and options will be extended by 10 minutes.

From 3 August 2026:

• Stock futures and options will trade from 9:15 AM to 3:40 PM
• Index futures and options will trade from 9:15 AM to 3:40 PM
• Commodity futures and options timings will remain unchanged

Earlier, stock and index futures and options closed at 3:30 PM.

The additional 10 minutes will allow traders to adjust or hedge their positions while the final closing price of the underlying stock is being determined through CAS.

How Will the Closing Auction Session Work?

CAS will operate from 3:15 PM to 3:35 PM and will be divided into four stages.

1. 3:15 PM to 3:20 PM: Reference Price Calculation

Regular trading in F&O-eligible stocks will stop at 3:15 PM.

During the next five minutes, the exchange will calculate a reference price. Eligible open orders from the regular trading session may also be transferred into CAS.

The reference price will be based on the volume-weighted average price of trades conducted between 3:00 PM and 3:15 PM.

Fresh orders cannot be placed during this period.

2. 3:20 PM to 3:25 PM: Market and Limit Order Entry

Investors can place both market and limit buy or sell orders during this stage.

However, these orders will not execute immediately.

They will be collected by the exchange and matched later through the auction process.

3. 3:25 PM to 3:30 PM: Limit Order Entry

Only limit orders can be placed during this period. Market orders entered during the earlier window cannot be modified or cancelled at this stage.

The order-entry window will close randomly between 3:28 PM and 3:30 PM. This random closure is intended to discourage traders from placing large orders at the final possible second.

4. 3:30 PM to 3:35 PM: Order Matching

The exchange will match eligible buy and sell orders and determine the stock’s official closing price. The final price will generally be the price at which the maximum quantity of shares can be executed.

If the exchange cannot discover an equilibrium price, it may use the previously calculated reference price as the official closing price.

What Happens to Existing Orders at 3:15 PM?

Eligible unexecuted limit orders from the regular trading session may be transferred into CAS. However, certain orders may not be carried forward. These include:

• Stop-loss orders
• Iceberg orders
• Orders outside the permitted CAS price range

Such orders may be cancelled when regular trading ends at 3:15 PM. During CAS, the permitted price range will generally be limited to 3% above or below the reference price calculated by the exchange.

What Changes for Delivery and MTF Investors?

For investors buying or selling F&O-eligible stocks through delivery or Margin Trading Facility, continuous trading will end at 3:15 PM.

Orders placed during the CAS order-entry period will not execute immediately. They will remain pending until the exchange completes the auction matching process.

The final execution price may also differ from the stock’s last traded price at 3:15 PM.

The executed quantity, official closing price and final order status will become available after order matching is completed.

For stocks that are not eligible for F&O trading, regular trading will continue until 3:30 PM as before.

What Changes for Intraday Traders?

Intraday traders need to be more careful because continuous trading in CAS-eligible stocks will end at 3:15 PM.

On INDmoney, the intraday square-off window for F&O-eligible stocks will move 10 minutes earlier.

From 3 August 2026:

• Intraday positions in F&O-eligible stocks may be squared off from 3:10 PM onwards
• Earlier, the square-off process began from 3:20 PM
• There is no change for stocks that are not eligible for F&O trading

This means traders holding an open intraday position in a CAS-eligible stock should manage or close it before the revised square-off window begins.

Square-off timings can differ across brokers. Traders should therefore check the timing displayed on their trading platform instead of waiting until the final few minutes.

Can You Trade F&O-Eligible Stocks After 3:15 PM?

Yes, but the trading process will be different. Once continuous trading ends, eligible stocks will move into CAS.

Investors will be allowed to place permitted market or limit orders during the specified auction windows.

However, these orders will not be matched continuously against orders from other investors. They will be collected and executed together at the final auction price.

Equity futures and options will continue trading normally until 3:40 PM.

What Is the Post-Close Session Timing?

After the closing auction and the extended derivatives session, the post-close session in the cash market will operate from 3:50 PM to 4:00 PM. During this session, eligible trades will be executed at the official closing price determined through CAS.

Simple Example of How CAS Will Work

Suppose an F&O-eligible stock is trading at ₹1,000 shortly before 3:15 PM. At 3:15 PM, continuous trading in the stock stops.

The exchange then calculates a reference price using trades conducted between 3:00 PM and 3:15 PM. Assume this reference price is ₹1,002.

During the CAS order-entry window, investors place buy and sell orders at different prices. The exchange may find that the maximum quantity of shares can be matched at ₹1,004.

In this case:

• Eligible orders will be executed at ₹1,004
• ₹1,004 will become the stock’s official closing price
• Some orders may remain unexecuted if there is insufficient matching quantity

This also means that a market order placed during CAS is not guaranteed to execute at the stock’s last traded price before 3:15 PM.

Important Timings to Remember

From 3 August 2026, the market will effectively have different closing timelines:

• 3:15 PM: Continuous trading ends for stocks covered under CAS
• 3:30 PM: Regular trading ends for stocks not covered under CAS
• 3:35 PM: CAS order matching is completed
• 3:40 PM: Trading in equity futures and options ends
• 3:50 PM to 4:00 PM: Post-close cash-market session

Before placing an order near the market close, investors should check whether the stock is eligible for futures and options.

Intraday traders should also manage their positions before the revised square-off window begins.

Final Takeaway

The introduction of CAS changes both how the closing price of major stocks is calculated and how investors can place orders near the end of the trading day.

For long-term investors, the main change is that orders in F&O-eligible stocks after 3:15 PM will enter an auction instead of executing immediately.

For intraday traders, the key change is the earlier square-off window for CAS-eligible stocks.

For F&O traders, the market will remain open until 3:40 PM, providing additional time to manage positions while the underlying stocks go through the closing auction.

Investors and traders should check whether a stock is covered under CAS and avoid leaving important orders until the final few minutes of the session.