Volumedraws on the price

The bars along the bottom. A move on heavy volume has conviction behind it; the same move on thin volume often gives itself back.

On this chart: Per-bar, colored by the bar's direction.

Shares traded per bar, drawn along the chart's base and colored by the bar's direction. Volume is the market's turnout figure — how much money actually changed hands at these prices, as opposed to where a thin tape drifted.

Volume confirms or undercuts the price action it accompanies. A breakout on triple average volume was bought by size; the same breakout on half average volume was mostly an absence of sellers. Climactic volume — a huge spike after an extended move — often marks the crowd arriving all at once, which is how moves end.

A support level that held on heavy volume was defended with real money — context for a put strike sitting beneath it. A capitulation-volume flush is also the profile where implied volatility, and with it put premium, spikes hardest on quality names.

Like everything in this guide, these are descriptions of conditions and reference levels — context for your own decisions, not instructions to trade.