You may check NIFTY or SENSEX at 3:15 PM and assume that you are seeing the closing value. A few minutes later, you may find a different official close because eligible stocks enter the Closing Auction Session, also called CAS.
You can follow this change on the AlgoTest Indicative Price Terminal. It lets you track where supported stocks and indices may close while CAS is running.
Track Live Indicative Closing Prices on AlgoTest
The terminal brings indicative prices into one searchable screen. You can track NIFTY 50, SENSEX, BANK NIFTY, MIDCPNIFTY, FINNIFTY, and eligible stocks.
For each supported instrument, you can check.
Its indicative closing price.
Its spot last traded price, when available.
The difference between the spot price and indicative close.
A chart of how its indicative price changed during the session.
You can view one minute close prices without logging in. You can sign up or log in to see live indicative price updates during CAS.
You can also learn more about CAS here.
What Is the Indicative Closing Price
The indicative closing price is the price at which a stock may close if the auction ends at that moment.
It is a live estimate, not the confirmed closing price. It changes as people place, change, or cancel orders. The exchange confirms the final price after it closes order entry and matches eligible orders.
Suppose a stock stops regular trading at Rs 1,000 at 3:15 PM. Its indicative price may move to Rs 1,006 as new orders enter. It may move again before the final close is set.
This is why the last traded price and the official closing price may not be the same.
How Does CAS Work
CAS helps the exchange discover the closing price of eligible stocks. In the first phase, it applies to cash market stocks that have derivative contracts.
Under the current NSE Closing Auction Session rules, CAS runs from 3:15 PM to 3:35 PM.
3:15 PM to 3:20 PM. The exchange moves from regular trading to CAS and calculates the reference price. This reference price uses the volume weighted average price of trades from 3:00 PM to 3:15 PM.
3:20 PM to 3:25 PM. You can place, change, or cancel market and limit orders.
3:25 PM to 3:30 PM. You can place, change, or cancel only limit orders. The system closes order entry at a random time during the last two minutes.
3:30 PM to 3:35 PM. The exchange matches orders and confirms the closing price.
The exchange first looks for the price at which the highest number of shares can be traded. If more than one price meets this rule, it checks the unmatched order quantity. It may also check which price is closest to the reference price.
Check out: Nifty Expiry Day: 7 Rules Every Options Trader Should Follow (2026)
Why Is the Indicative Price Useful
The last traded price may pause during CAS, while the indicative price keeps changing with the auction order book. Tracking it helps you understand why the final close may differ from the value you saw at 3:15 PM.
You can also see whether the auction points to a higher or lower close. This may be useful on volatile days and expiry days, when a change in the closing index value can affect option positions.
How to Use the AlgoTest Indicative Price Terminal
Open the Indicative Price Terminal. Check the NIFTY 50 and SENSEX cards for a quick market view.
Next, use the search bar to find an index or stock. Compare the indicative close with the spot price. You can then open the chart to see whether the expected closing price moved higher or lower during CAS.
This helps you understand why the final close may differ from the 3:15 PM value, especially on volatile days.
Related: Sensex Expiry Day: Date, Timing & 2026 Trading Guide
What You Should Keep in Mind
The indicative price is not a guaranteed closing price. It can change until the order entry window ends. You should not use it as a standalone trading signal.
Use it to understand the closing auction and follow where the market may settle. Always wait for the exchange to confirm the final closing price before treating it as official.
Track Indicative Closing Prices With AlgoTest
You do not need to check each stock or index separately during CAS. The AlgoTest Indicative Price Terminal brings supported stocks and indices into one screen.
With AlgoTest, you can:
→ Track indicative closing prices during CAS.
→ Compare the indicative close with the spot LTP.
→ View price changes on a one-minute chart.
→ Search for supported stocks and indices.
Follow where the market may close before the final price is confirmed.