Why does the last traded price look “paused” during the auction?

The continuously updating last traded price for F&O stocks pauses during 3:15 to 3:20 pm. From 3:20 pm onwards, you’ll see an indicative closing price that updates as orders come in. The official close is confirmed at the end of the window (around 3:35 PM). Index values (NIFTY,BANKNIFTY, SENSEX and BANKEX) continue to update with an indicative closing price throughout CAS.