Intraday trading is about buying and selling the stock on the same day such that the net position at the end of the day is zero. You can buy and sell the position or you can also sell the stock and buy it back before the end of day. Whatever the profits and losses in intraday trading; they are credited or debited to your trading account on the same day. Intraday transactions are closed out by the broker if the trader forgets to close it out. Since the net position is zero at the end of the day, there is no impact on the demat account of the trader as there is no delivery.