Trading Volume

Volume is the number of shares traded in a period; it shows how much attention and liquidity a stock has.

Why investors care

High volume confirms moves; low volume makes prices easier to push around.

Where people go wrong

Volume alone says nothing about direction; pair it with price action.

In the real market

A small stock breaks out to a six-month high on double its average volume, and chart enthusiasts call it a genuine breakout. A skeptic checks the number of trades: 300,000 shares changed hands, tiny in absolute terms. One institution or even a single large trader could have produced the move. When the big seller hits the tape the next day, the stock gives back the entire gain. The scenario shows why volume must be judged in context — a spike on a normally dormant stock is a ripple, not a wave.

Using it in practice

Look at volume relative to a stock’s own average, not absolute numbers. A breakout on rising volume is far more credible than one on shrinking volume, and a quiet drift on low volume often precedes a break.

Example in numbers

Key takeaway

Volume is the market’s attention gauge, and it gives every price move a vote of confidence — or a warning. A breakout on rising volume is real participation; one on shrinking volume is a thin tape that can reverse in seconds. Judge volume against a stock’s own average, not absolute numbers, and pair it with price action and trend. High volume confirms moves and means easy exits; low volume makes prices easy to push around and hard to leave.

Definitions reviewed by the Investing Glossary editorial team.