NSE Revamps Pre-Open Session: Market Orders Get Priority

The National Stock Exchange has revised its pre-open session framework, prioritizing market orders over limit orders. The session maintains its 9:00 am to 9:15 am timing, with a revamped order collection and matching process. Market orders now have a crucial window for submission before 9:05 am.

The National Stock Exchange (NSE) of India has introduced significant changes to its pre-open session framework. Effective from Monday, the revised system now prioritizes market orders over limit orders during the order matching process. This adjustment is seen as an effort to bring the pre-open session closer in alignment with the Closing Auction Session (CAS) principles.

Under the updated guidelines, the pre-open session retains its standard 9:00 am to 9:15 am schedule. However, traders should note the altered process for order submission, collection, and matching within this 15-minute duration. Market and limit orders can be placed between 9:00 am and 9:05 am, while only limit orders will be accepted between 9:05 am and 9:10 am. A crucial change is that market orders must be submitted in the first five minutes.

The order matching process occurs from 9:10 am to 9:12 am. Initially, market orders will be matched with other market orders based on a time priority system, followed by any remaining market orders matched against limit orders using a price-time priority. The changes underscore a clearer distinction between order collection and the subsequent matching and price discovery phase, making the timing and type of orders more critical. In related updates, the NSE mentioned that special term orders, such as Stop Loss and Immediate or Cancel, will not be permitted during the order entry phase.