The difference exists because the Last Traded Price (LTP) represents the actual last traded price, while the exchange calculates the closing price. For non-F&O stocks, the exchange calculates the closing price as a weighted average of the last 30 minutes of trading (3:00 PM to 3:30 PM). For F&O segment stocks (Phase 1), the closing price is determined during the Closing Auction Session (CAS) based on matching order books from 3:15 PM to 3:30 PM.