Cumulative Volume

Cumulative Volume adds up every trade in a contract from the market open at 9:15am IST, giving a continuously rising line through the session rather than the volume-per-bar figures shown on most candlestick charts. Because it never resets intraday, it shows the shape of participation across the day, whether activity is front-loaded near the open, builds steadily, or spikes late as the 3:30pm close approaches, which is common on Nifty and Bank Nifty weekly expiry days.

Retail F&O traders use cumulative volume mainly as a pace check: comparing today’s running total at, say, 11am against the same time on an average recent day tells them whether the session is unusually active or unusually quiet, which in turn affects how much weight to give to price moves happening right now. It is also a standard input alongside VWAP, since VWAP itself is calculated by weighting price against cumulative traded volume through the day.

A sudden steepening in the cumulative volume curve, a sharp uptick in its slope rather than the level itself, is often more informative than the total figure, since it flags the exact point in the session where fresh money entered. Traders combine this with strike-level activity from Volume Gainers screens and open interest change to judge whether that burst reflects real conviction, an approach broadly described as Volume-OI Confluence, rather than simply reacting to the raw number.