Volume
Family XII · Other terms
Not to be confused with volume indicator.
Volume is the total quantity of a security or contract traded during a specified period, typically reported as shares, contracts, or units exchanged. It reflects how much trading activity occurred, not whether prices rose or fell. Volume is usually shown alongside price data and is often compared with its own recent average to judge whether activity is unusually high or low.
What volume counts
Volume counts completed transactions, so every trade has a buyer and a seller and the reported figure is the number of units that changed hands. For shares, the unit is normally one share; for futures and options, it is one contract; for some markets, it may be reported in lots or board lots. Reported volume can differ from turnover, which is volume multiplied by price.
Exchanges and data vendors may report volume in different ways, and the exact conventions vary by market, instrument, and data source. Figures are often split into regular trading hours and extended hours, and some feeds include off-exchange or block trades while others exclude them.
Worked example
A trader compares a stock's daily volume with its 20-day average to judge whether the session was active.
The result shows today's activity is 50% above the recent average, which is a descriptive comparison and not a forecast of future price movement.
How volume is used
Volume is used to gauge liquidity and participation. Higher volume generally means more traders are active and that positions can be entered or exited with less price impact, though the relationship depends on the instrument and market conditions. Low volume can mean wider spreads and greater sensitivity to individual orders.
Volume is also compared across sessions to confirm or question price moves. A price change on unusually high volume is often described as having more participation behind it, while a move on thin volume is described as less broadly supported. These are conventions of interpretation, not rules that predict direction.
Often confused with
- volume indicator
- Volume is the raw quantity traded, while a volume indicator is a derived study that applies a formula to volume data, such as a moving average or an oscillator; the visible sign is that volume is reported directly by the market data feed, whereas a volume indicator is plotted as a calculated line or histogram.