Short answer

Your P&L on Arrow changes after 3:30 PM because the system switches from using the Last Traded Price (LTP) to the official closing price declared by the exchange.

How P&L calculation works for equity holdings

During trading hours (9:15 AM to 3:30 PM), Arrow uses the LTP or live price to calculate your P&L for stocks on the holdings and positions page. After the market closes at 3:30 PM, the exchange declares the official closing price, which is the weighted average of trades in the last 30 minutes (3:00 PM to 3:30 PM). Your holdings page then switches to this closing price to calculate your stock values and P&L.

How P&L calculation works for F&O positions

For futures and options, Arrow calculates your P&L differently depending on the time:

9:15 AM to 3:30 PM: Uses the current LTP

3:30 PM to midnight: Uses the LTP at 3:30 PM

Next day until 9:15 AM: Uses the previous day’s closing price

Since the last traded price and closing price often differ, you will see variations in your P&L accordingly.