Indian equity markets trade Monday to Friday, excluding declared holidays. NSE and BSE publish a holiday list at the start of each calendar year. There is no Saturday or Sunday trading, and a special one-hour Muhurat session is held on Diwali each year as a tradition.
Pre-open session — 9:00 to 9:15 AM
The first fifteen minutes are not normal trading. They are an auction, designed to find a sensible opening price rather than letting the first trade of the day set it.
| Time | What happens |
|---|---|
| 9:00 – 9:08 | Orders can be placed, modified and cancelled. Nothing is matched yet. |
| 9:08 – 9:12 | No new orders. The system computes the opening price and matches. |
| 9:12 – 9:15 | Buffer period, transition to normal trading. |
The opening price is the price at which the maximum quantity can be executed. That is the whole logic: whichever price clears the most shares wins.
Normal trading session — 9:15 AM to 3:30 PM
Continuous trading. Orders match instantly against the order book whenever prices cross. This is where the overwhelming majority of trading happens.
No lunch break — Indian markets run straight through.
The close: how the closing price is decided
The closing price matters far more than beginners assume. It is used to value mutual fund portfolios, to mark your positions, to settle derivatives, and to compute index levels.
Historically, NSE and BSE computed the closing price as the volume weighted average price (VWAP) of the last 30 minutes of trading, from 3:00 to 3:30 PM.
That is now changing. SEBI has introduced a Closing Auction Session (CAS) for the equity cash segment, rolled out in phases and starting with stocks that have derivatives available on them. Under CAS, instead of an averaging formula, the closing price is discovered by an auction, much like the pre-open session.
The shape of the CAS day for an affected stock:
| Time | What happens |
|---|---|
| 3:00 – 3:15 | Continuous trading, and the VWAP over this window becomes the auction's reference price |
| 3:15 – 3:20 | Transition out of continuous trading; reference price computed |
| 3:20 – 3:25 | Auction order entry: limit and market orders, modification and cancellation allowed |
| 3:25 – 3:30 | Limit orders only; market orders locked; a random close in the final couple of minutes |
| 3:30 – 3:35 | Matching, and confirmation of the closing price |
Orders in the auction are held inside a price band around the reference price. The closing price is the equilibrium price — the one at which the largest quantity can trade.
For stocks not yet covered by CAS, continuous trading runs to 3:30 PM as before.
Post-closing session — after the close
For a short window after the close, you can place orders at the closing price — no price entry, just quantity. These are matched at the closing price if a counterparty exists.
Useful if you are content to transact at the day's official close. Not useful if you care about the price you get.
After-Market Orders (AMO)
You can place an AMO at night or early morning for the next trading day. It is not executed overnight; it sits with your broker and is pushed to the exchange when the market opens.
Handy if you cannot watch the screen during the day. But be careful: a market AMO executes at whatever the opening price turns out to be, and after significant news the open can be far from yesterday's close. A limit AMO is safer.
A practical note on the opening
The first fifteen to thirty minutes are the most volatile part of the day. Overnight news is being absorbed, spreads are wide, and prices can swing sharply and then reverse.
There is nothing wrong with trading then, but a market order at 9:15 AM in a stock that is not heavily traded is one of the easier ways to get a bad fill.
Key takeaways
- Equity markets trade Monday to Friday, 9:15 AM to 3:30 PM, with a pre-open auction from 9:00 AM.
- The pre-open auction finds the price that lets the maximum quantity trade, which prevents a chaotic open.
- The closing price is moving from a 30-minute VWAP to a Closing Auction Session, rolled out in phases.
- For CAS stocks, continuous trading ends at 3:15 PM and the close is decided by auction.
- AMO orders sit with your broker overnight and are sent at the open — prefer limit over market.
Check your understanding
0 of 3 answered