What It Means
Day trading means buying and selling the same stock or contract within a single trading session, closing every position before the market closes at 3:30 PM. No shares actually move into your demat account — the position is squared off the same day it's opened.
How It Works
Day trading is placed as an "intraday" order type with most brokers, which typically offers higher leverage than a delivery trade since the broker knows the position won't be held overnight. That leverage cuts both ways: it amplifies gains on a correct call and losses on a wrong one, and if you don't square off manually before the cutoff time, most brokers auto-square-off the position for you — sometimes at a worse price than you'd have chosen yourself.
Warning
Forgetting to square off an intraday position manually and relying on the broker's auto-square-off can cost you a worse exit price, especially in a fast-moving or illiquid stock near the cutoff window.