What is the pre-market (pre-open) session?

NSE and BSE run a pre-open call auction from 9:00-9:15 AM before continuous trading begins. Buy and sell orders are collected and matched at a single equilibrium price, which becomes the reference price for the day's opening.

What are the phases of the pre-open session?

Order collection runs 9:00-9:08 AM, order matching and price discovery runs 9:08-9:12 AM, and a buffer period runs 9:12-9:15 AM before continuous trading opens.

Does the index move continuously during pre-market?

No — there is no continuous trading during the pre-open session, so the index reflects the discovered equilibrium price as it forms rather than a smooth intraday trend, similar to how the Closing Auction Session behaves at the other end of the day.

SENSEX — Pre-Market Session Chart

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Live 1-minute SENSEX chart starting from the exchange's pre-open session (9:00-9:15 AM) through the full trading day. The index reflects the discovered equilibrium price as the pre-open call auction forms, then transitions into normal continuous-trading movement from 9:15 AM onward.

SENSEX — Full Day Chart

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Timeframe:

O — H — L — C —

How the Pre-Open Session Works

9:00 AM – 9:08 AM

Order Collection

Buy and sell orders are collected into the pre-open auction order book. No trades execute during this phase.

9:08 AM – 9:12 AM

Order Matching & Price Discovery

The exchange matches orders at the single price yielding maximum executable volume — the discovered equilibrium price.

9:12 AM – 9:15 AM

Buffer Period

A transition window between the auction and the start of continuous trading.

9:15 AM onward

Continuous Trading

Normal market hours begin — the index moves tick-by-tick like any other time of the trading day.