Volume represents the total number of shares, contracts, or units traded during a specific time period. It is the most fundamental confirmation tool in technical analysis β 'price is what, volume is why.'
Core Principles
- Trend confirmation: Rising prices with rising volume confirms a strong uptrend. Rising prices with declining volume warns of a weak rally that may reverse
- Selling climax: Extremely high volume during a sharp decline often marks capitulation β a potential bottom as the last sellers exit
- Breakout validation: A price breakout above resistance on above-average volume is more reliable than one on light volume
- Volume precedes price: Volume often turns before price does. Declining volume during an uptrend is an early warning of trend exhaustion
Volume Indicators
- On-Balance Volume (OBV): Running total that adds volume on up days and subtracts on down days. Developed by Joe Granville. Divergence between OBV and price signals potential reversals
- Volume Profile: Shows volume traded at each price level over a period, identifying high-volume nodes (support/resistance) and low-volume nodes (price tends to move quickly through these)
- VWAP (Volume Weighted Average Price): Institutional benchmark β large orders are often benchmarked against VWAP. Price above VWAP indicates bullish sentiment for the day
Market-Specific Context
- Equity markets: Average daily volume for the S&P 500 component stocks is roughly 3-4 billion shares per day on NYSE/NASDAQ combined
- Options: Volume vs. Open Interest distinguishes new positions from closing positions
- Crypto: Volume data is less reliable due to wash trading on some exchanges
The 'Volume Dry-Up' Pattern
When volume drops to extremely low levels during a consolidation, it often precedes a significant price move. Combined with a Bollinger Squeeze, this creates a 'coiled spring' setup.