The National Stock Exchange has announced the introduction of a pre-open session for equity futures and options (F&O) starting from December 8, 2025. This session is designed to facilitate the discovery of opening prices in index and stock futures before regular trading commences, similar to the existing pre-open call auction in the equity cash market.
The primary objective is to mitigate abrupt price fluctuations at the market open and provide traders with a more comprehensive understanding of overnight market sentiment.
The pre-open session will run for 15 minutes, from 9:00 am to 9:15 am. During the initial phase, which allows traders to place, modify, or cancel orders, the window will close randomly between 9:07 and 9:08 am to prevent last-minute order alterations.
Following the order entry period, a single opening price will be determined based on supply and demand, and orders will be matched at that price. This price discovery and matching phase will conclude at 9:12 am, followed by a brief buffer period until 9:15 am when regular continuous trading will commence.
Orders that are matched in the pre-open session cannot be canceled, while unmatched orders will move forward to the normal trading session. Limit orders will retain their original timestamp, and market orders without matches will convert into limit orders at the opening price.
Initially, the pre-open session will be applicable only to current-month futures on indices and individual stocks. In the last five trading days before expiry, the mechanism will extend to next-month futures. Far-month contracts, options, spread orders, and futures affected by corporate actions will not be included.
Margin rules that apply during regular trading will also be enforced during the pre-open session. Traders without sufficient margin will not be able to place orders. Special order types like stop-loss or IOC will not be permitted during this period, with only regular limit and market orders allowed.
For active F&O traders, the pre-open session offers a structured approach to react to overnight developments in global equities, commodities, currencies, or significant news outside market hours. It provides a clearer reference price before continuous trading starts, enhancing transparency by displaying indicative opening prices and order imbalances to help traders gauge market direction.
Mock trading for the new system is scheduled for December 6 to allow brokers and trading platforms time to adjust before the live implementation.