Glossary / Market structure

Volume

Volume is the number of shares that changed hands over a period. Every trade has a buyer and a seller, so volume counts transactions — it does not measure net buying or net selling.

How it is measured

How is volume measured?

Sum the shares executed across all venues over the period. Consolidated volume aggregates every exchange and reporting facility; single-venue figures are lower and not comparable to it. Volume is heavily concentrated around the opening and closing auctions, so any intraday comparison has to be against the same time of day.

Why it matters

Why does volume matter to a swing trader?

Volume is the participation dimension underneath every price move: the same percentage change on very light and very heavy trading are different events, because one describes a price agreed by few participants and the other a price agreed by many. The persistent misreading is treating volume as directional. A session with heavy volume and a falling price tells you many participants transacted, not that sellers outnumbered buyers — by construction, they cannot.

Related

See this in the product

The live scanner · Full methodology

Related terms

Relative volume
Relative volume compares the volume traded in a session to that same security's own average volume over a recent window, expressed as a multiple.
Average dollar volume
Average dollar volume is the value traded in a typical session — shares traded multiplied by price — averaged over a recent window.
Accumulation / distribution
Accumulation describes building a position gradually over many sessions to avoid moving the price; distribution describes unwinding one the same way.
Breakout
A breakout describes price moving beyond a level that had previously contained it — a prior high, a prior low, or the boundary of a range price had been oscillating inside.

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General information about market vocabulary, written to be descriptive rather than prescriptive. Not investment advice — see the risk disclosure.