Volume

The number of shares or contracts traded in a security over a given period, shown as histogram bars beneath price, used to gauge the conviction behind a move.

Volume measures participation — the total quantity of shares or contracts that changed hands during a bar's time period. It is plotted as a histogram of vertical bars below the price chart, one per period, often colored to match whether the bar closed up or down. Together with price (the OHLC values), volume is one of the two primary raw inputs to nearly all technical analysis.

Volume is read as a measure of conviction. A price move on heavy volume reflects broad participation and is considered more trustworthy than the same move on light volume, which may be noise. Breakouts are widely expected to occur on rising volume; a breakout on weak volume is suspect and prone to failure. Climactic volume spikes often mark exhaustion at the end of a move, while steadily declining volume during a trend warns that interest is waning. Volume also underpins a family of derived tools — VWAP, On-Balance Volume, and Volume Profile all build on it.

Volume's reliability as a signal depends heavily on the market and data source. Exchange-listed equities and futures report accurate, centralized volume; in fragmented or over-the-counter markets — much of spot forex, for example — there is no single true volume figure, only broker-specific tick counts, which limits volume analysis there. Volume is best used as a confirming second factor — does participation support the price move? — rather than a standalone signal, since heavy volume alone says activity was strong without revealing which side won.

This definition is for informational and educational purposes only. Nothing on Finance Compass constitutes financial, investment, or trading advice. Always conduct your own research and consult a qualified professional before making financial decisions.