Revision in Closing Auction Session (CAS) Timings and Derivatives Trading Hours
As per the SEBI circular dated 15th October 2026, changes have been made to the Closing Auction Session (CAS) framework, including market timings, order handling and settlement price calculations for Stock and Index Derivatives.
The changes will come into effect from 7th December 2026. Additionally, changes to the transition of pending Limit and Iceberg Orders from the Continuous Trading Session (CTS) to CAS will take effect from 8th February 2027.
The key changes are as follows:
Closing Auction Session Timings
The Closing Auction Session will operate from 3:30 PM to 3:40 PM, with the following schedule:
Time | Activity |
|---|---|
3:30 PM to 3:31 PM | The reference price will be calculated, and the market will transition from continuous trading to CAS. |
3:31 PM to 3:36 PM | Market Orders and Limit Orders can be placed. |
3:36 PM to 3:40 PM | Only Limit Orders can be placed, modified or cancelled. Market Orders cannot be modified or cancelled. |
Between 3:38 PM and 3:40 PM | Order entry will close at a system-driven random time. |
After random closure | Buy and sell orders will be matched at a single matching price determined by the exchange. This will become the official closing price. |
The reference price for CAS will be determined using the Volume Weighted Average Price (VWAP) of trades executed during the last 15 minutes of the Continuous Trading Session.
If no trades occur during this period, the Last Traded Price (LTP) of the day will be considered. If no trades occur throughout the day, the previous trading day's closing price will be used, subject to applicable corporate action adjustments.
Changes to Derivatives Trading Hours
Segment | Trading Closing Time |
|---|---|
Equity Cash – Continuous Trading | 3:30 PM |
Closing Auction Session (CAS) | 3:40 PM |
Index Derivatives | 3:45 PM |
Expiring Index Derivatives (on expiry day) | 3:30 PM |
Stock Derivatives (including expiry day) | 3:45 PM |
Equity Cash – Post-Close Session | 3:50 PM to 4:00 PM |
Note: On expiry days, trading in expiring Index Derivative contracts will close at 3:30 PM. Stock Derivatives will continue trading until 3:45 PM, including on expiry days.
Changes to Settlement Price Calculation
The settlement prices for expiring Stock and Index Derivative contracts will be calculated using the VWAP during the last 30 minutes of the Continuous Trading Session.
Contract Type | Settlement Price Calculation |
|---|---|
Index Derivatives | Based on the underlying index value calculated using the VWAP of its constituent stocks during the last 30 minutes of continuous trading. |
Stock Derivatives | Based on the VWAP of the underlying stock during the last 30 minutes of continuous trading across stock exchanges. |
The exchanges will also publish indicative index values and VWAP information in real time during this period.
Important Points
- Market Orders and Limit Orders will be accepted during the applicable CAS order-entry window.
- Stop-loss Orders and new Iceberg Orders will not be accepted during CAS.
- Market Orders cannot be modified or cancelled during the final Limit Order entry period.
- Price bands for Stock Futures between 3:30 PM and 3:45 PM will be aligned with the applicable CAS price bands.
- Orders placed during CAS will be subject to applicable margin requirements at the order level, except eligible orders carried forward from continuous trading.
- The Post-Close Session in the Equity Cash segment will continue from 3:50 PM to 4:00 PM, with trades executed at the closing price.
Changes to Pending Orders
Effective from 8th February 2027
The following changes will apply to unexecuted orders carried forward from the Continuous Trading Session (CTS) to CAS:
- Eligible unexecuted Limit Orders will automatically carry forward to CAS, except Stop-loss Orders and orders outside the applicable CAS price bands.
- Unexecuted Iceberg Orders within the applicable price bands will carry forward as fully disclosed Limit Orders, unless the trader has opted out of the transition when placing the original order.
- Carried-forward Limit and Iceberg Orders will have higher time priority than new Limit Orders placed during CAS.
- Transitioned Iceberg Orders will have lower time priority than other carried-forward Limit Orders.
- Modifying a carried-forward order during CAS will change its time priority and make it subject to applicable order-level margin requirements.
Implementation Timeline
Changes | Effective Date |
|---|---|
Changes to CAS timings | 7th December 2026 |
Changes to Derivatives trading hours | 7th December 2026 |
Changes to settlement price calculation | 7th December 2026 |
Changes to CAS order types and price bands | 7th December 2026 |
Changes to pending Limit and Iceberg Order transition | 8th February 2027 |
Note: Traders placing orders near market close should plan their trades according to the updated timings and order-entry rules. Orders placed using features such as GTT, SIP and Scheduled Orders may be affected by the revised market schedule. The changes may also affect intraday (MIS) auto square-off timings. Any updates to FYERS-specific square-off timings will be communicated separately.
For complete details, please refer to the latest SEBI circular and the earlier notice below.
- SEBI Circular - Circular No: HO/47/11/11(3)2025-MRD-POD2/I/23843/2026 | Dated: 15th October 2026
- Earlier Notice | Dated: 29th July 2026
Important: The latest SEBI circular updates certain timings and operational provisions mentioned in the earlier notice. These changes will apply from their respective effective dates.