Pre-Open Session
The window before continuous trading begins in which orders are collected and matched in a call auction to set the opening price.
How it is identified
Test: orders may be entered and modified during the collection window but execute only at the single auction price
Unit
qualitative
In depth
India's equity pre-open runs from 9:00 to 9:08 for order entry, followed by a short matching phase, with continuous trading starting at 9:15. Its purpose is to absorb overnight information in an orderly way rather than through a chaotic first minute of trading. Only limit and market orders in eligible securities participate, and unmatched orders carry into the continuous session at the open. Traders who place market orders in the pre-open on news often discover that the auction price already reflects the news completely.
Worked example
Orders entered between 9:00 and 9:08 determine a single opening price. A market order entered at 9:07 on results published overnight fills at that auction price, capturing none of the move — the auction is where the move happened.
Illustrative figures, chosen so the arithmetic is easy to follow. Not a live price and not a valuation of any company.
Educational reference only
This entry explains what “Pre-Open Session” means. It is not investment advice and not a recommendation to buy or sell any security. Any numbers above are illustrative, not live prices, and nothing here predicts price direction or rates a stock. Consider your own circumstances and consult a SEBI-registered investment adviser before acting.