Hello Traders & Investors,
From Monday, 7 September 2026, the pre-open session in Equity Cash & Futures will work differently. The overall time window itself will not change, it’s still 9:00 AM to 9:15 AM. What changes is when you can use Market orders and when order entry actually stops. If you place orders in the pre-open session, this is for you.
Below is the table to understand exactly what’s going to happen in pre-open session now:
Let us go through each window one by one.
9:00 - 9:05 AM
Pre-Open Auction Session (PAS) starts. Order entry opens. Both Limit and Market orders can be placed, modified and cancelled. This is a bidding process only, no matching happens here. You will see the Indicative Open Price (IOP) or Equilibrium Price building up and shown in the price field in Dhan.
9:05 - 9:10 AM
Order entry continues, but only for Limit orders. You can place, modify and cancel Limit orders. Market orders can no longer be placed, and any Market order already sitting in the orderbook can neither be modified nor cancelled, it is locked in. For the same reason, you cannot modify an existing Limit order into a Market order in this window.
This session closes randomly, anytime between 9:08 and 9:10 AM. The exact second is system driven and is not announced, which is the whole point, so that nobody can time the last tick to influence the opening price. Practically, treat 9:08 AM as your deadline, not 9:10 AM.
9:10 - 9:12 AM
No more orders. All eligible orders are matched at the equilibrium price, and that price becomes the day’s opening price.
9:12 - 9:15 AM
Unexecuted orders transition into the Continuous Trading Session. The market opens for normal trading at 9:15 AM.
What is Equilibrium Price or Indicative Open Price?
The mechanism itself is not changing, and it works exactly the way it does in CAS.
The exchange does not match orders one by one the way continuous trading does. It collects all eligible buy and sell orders and asks a single question: at what price can the largest quantity of qty change hands? That price is the equilibrium price, and it becomes the opening price. Everyone who trades in the auction trades at that same single price.
How do orders get matched?
Matching happens between 9:10 and 9:12 AM, and Market orders get priority over Limit orders. The sequence is:
- Market orders match against Market orders, in time priority, at the equilibrium price.
- Any leftover Market orders match against Limit orders, in price-time priority.
- Remaining Limit orders match against Limit orders, in price-time priority.
This is why the 9:05 AM cut-off matters so much. A Market order placed in the first five minutes carries execution priority into the auction, but you are also accepting whatever the equilibrium price turns out to be, with no ability to pull the order back after 9:05.
For active traders, the adjustments are practical. Market orders are now a 5-minute decision. Place them between 9:00 and 9:05 AM, and treat them as final. After 9:05, they cannot be edited or cancelled. Limit orders stay flexible longer, but only till the random close. Build your routine around 9:08 AM, not 9:10 AM. Do not plan around Stop Loss orders in pre-open, they are not permitted in this session.
Taken together with CAS, both ends of the trading day now work the same way: a single, transparent price where the maximum volume can trade, discovered in a session that nobody can game at the last second.
Also, apart from this, the price band for both stock and index futures will be revised at 3:15 PM to ±3% of their reference price, calculated using the VWAP between 3:00 PM and 3:15 PM. Any pending orders outside the revised price band will be cancelled by the exchange.
Happy Trading