Traded Volume
Also called: volume, traded volume, trading volume meaning, what does volume mean in stocks, volume vs open interest.
How it is read
Volume is read as context beside price. It is not a signal on its own. A large move on unusually high activity is a different description from the same move on a thin book. A bar that is still forming is not comparable with completed ones. In derivatives it must be read alongside open interest. The two answer different questions. Volume is how much traded in the interval. Open interest is how many contracts remain open at the end of it.
What it does not tell you
Volume identifies nobody. It does not reveal an institution building a position. It does not reveal a hedge against exposure held elsewhere. It does not reveal one leg of a multi-part position. A rise in volume says more changed hands. It does not say who was buying. High volume is not bullish. Low volume is not bearish. Both occur in advances, declines and reversals. Comparing figures across instruments, segments or unit conventions is the most common error. It works only if the units are matched first. Volume added up across the session is not the same series as per-bar volume.
See it in an experiment
Change one input in Market X-Ray and watch what happens.
Market X-Ray: Open Interest — What actually changes when open interest moves?
Market X-Ray: Option Chain — Which option-chain columns answer my question?
Related concepts
Open Interest vs Volume: Counting Contracts, Not Trades
Watch candles on the practice desk
Open the NIFTY and BANKNIFTY practice desk. Compare the chart with the idea explained here.