From 7 September 2026, the equity pre-open session's order-entry window gets longer: you can place, modify or cancel orders from 9:00 to 9:08 AM, and the window then closes at a random moment between 9:08 and 9:10 AM. Everything else about the pre-open — the opening-price auction and normal trading starting at 9:15 AM — works as before.
The pre-open session is the 15-minute call auction the exchange runs before normal trading begins. It decides a stock's official opening price. SEBI has revised the pre-open session for the equity cash and derivatives segments across NSE and BSE, to align it with the newly introduced Closing Auction Session (CAS).
What is changing?
- Until 5 September 2026, order entry ran from 9:00 to 9:07 AM, with a random close between 9:07 and 9:08 AM.
- From 7 September 2026, order entry runs from 9:00 to 9:08 AM, with a random close between 9:08 and 9:10 AM.
Which segments does this apply to?
Both the equity cash segment and the equity derivatives (F&O) segment, on NSE and BSE.
- Cash segment: all equity securities, including SME securities, partly paid-up securities, and InvITs/REITs.
- Derivatives segment: current-month futures contracts on stocks and indices. In the last five trading days before the current-month expiry, it extends to next-month futures as well. Options and spread contracts have no pre-open session.
When does the pre-open run?
| Time | Stage |
|---|---|
| 9:00 – 9:08 AM | Place, modify or cancel orders — limit and market. Market orders are converted to limit orders through MPP. |
| 9:08 – 9:10 AM | The order window closes at a random moment — any time between 9:08 and 9:10 AM. |
| 9:10 – 9:12 AM | Opening price is discovered and orders are matched. No order changes allowed. |
| 9:15 AM | Normal trading begins, as usual. |
What about market orders on Rupeezy?
On Rupeezy, every market order placed in the pre-open goes to the exchange through Market Price Protection (MPP). MPP converts your market order into a limit order with a price cap based on the security type and price, instead of sending it open-ended.
From 9:05 AM, the exchange no longer accepts plain market orders in the pre-open. Because Rupeezy sends the exchange a limit order — not a plain market order — that restriction does not apply to you: you can place, modify and cancel MPP orders right through the order entry period, exactly as you do today. Your order is matched as a limit order, so it does not receive the matching priority that a plain market order would.
How is the opening price worked out?
The opening price is the equilibrium price — the price at which the maximum quantity can be traded, based on all the buy and sell orders collected during the order entry period. Both limit and market orders count towards this calculation.
If more than one price allows the same maximum quantity, the exchange picks the price with the smallest unmatched (imbalance) quantity. If more than one price still qualifies, it picks the price closest to the previous day's closing price.
Orders are then matched in this sequence:
- Market orders against market orders, in time priority, at the equilibrium price.
- Any remaining market orders against limit orders, in price-time priority.
- Limit orders against limit orders, in price-time priority.
Two special cases:
- If only market orders exist on both the buy and sell sides, orders match at the previous close or base price, and that becomes the opening price.
- If no price is discovered in the pre-open, the price of the first trade in the normal market becomes the opening price.
Which order types can I use during the pre-open?
- Accepted: limit orders, and market orders (placed through MPP on Rupeezy).
- Not accepted: Stop Loss (SL), Immediate or Cancel (IOC) and Disclosed Quantity (DQ) orders.
Please note: GTT (Good Till Triggered) orders are not triggered during the pre-open session, between 9:00 and 9:15 AM. You can place a GTT order at any time.
Lot size, tick size and price bands are the same as in the normal market. All orders are checked against your available margin before they are accepted.
What happens to my unmatched orders?
Orders that do not match in the pre-open are carried into the normal market. Because Rupeezy sends every pre-open order as a limit order — including market orders converted through MPP — your unmatched orders move to the normal market at the price they were placed at, keeping their original time stamp. They are not repriced to the opening price.
These orders cannot be modified or cancelled between the end of the pre-open session and the start of normal trading at 9:15 AM.