Volume Indicator on a Live Bitcoin Chart

What it shows

One bar per candle, sitting at the bottom of the price pane with no price scale of its own. Each bar takes one of two colours, an up colour or a down colour, depending on how the candle closed. The thin line over the bars is a simple average of volume over the last 20 candles.

How Pravex works it out

1. Each bar is the candle’s traded volume exactly as the data feed reports it. Pravex does not change or scale it.
2. The colour is decided by one comparison. By default a candle that closed at or above its own open gets the up colour, and one that closed below its open gets the down colour.
3. Turn on Colour bars against the previous close and the comparison changes: the candle’s close is checked against the previous candle’s close instead of its own open. The very first candle on the chart still uses its open.
4. The average line adds up the last 20 volume values (the Average length) and divides by 20. It has no point until that many candles are on the chart.

Settings

Setting	Default	What changing it does
Average length	20	Sets the window of the line drawn over the bars. A shorter window follows each burst of volume closely; a longer one shows what is normal for the market over a longer stretch.
Colour bars against the previous close	Off	Off colours each bar by close against its own open. On, it colours by close against the previous close, so a candle that opened with a gap and closed lower than it opened can still get the up colour if it closed above the last close.

How traders read it

Traders read volume as the weight behind a move. A breakout through a level on a bar far above the average line shows that many orders went through; the same breakout on a short bar had little behind it.

The average line gives you a yardstick. Bars well over it are busy candles, bars under it are quiet ones. On bitcoin you often see bars shrink through a pullback and swell again once price resumes; when the second push comes on thin bars, it has less behind it.

Colour adds direction to the size. A tall bar in the down colour says sellers took part heavily in that candle. Switch to previous-close colouring if you care about the step from one close to the next more than the candle’s own body.

When it misleads

Volume tells you how much traded, not who was buying and who was selling. Every trade has both sides, so a tall down-coloured bar does not prove selling pressure in itself. The number also depends on the venue: it counts only what this exchange saw, and a quiet hour in the night session looks small whatever the price does. Bars on the candle still forming grow as trades come in, so judge a bar only once its candle has closed.

Questions and answers

Is a volume bar the number of trades?

No. It is the amount traded in that candle as the exchange reports it, so one big order and a hundred small ones can make the same bar. Pravex draws the figure unchanged.

Why is a volume bar up-coloured on a falling candle?

That happens only with Colour bars against the previous close switched on. The bar then compares this close with the last one, so a candle that fell from a gap-up open but still closed above the prior close gets the up colour.

Can I see volume on the gold chart?

Spot gold trades between banks and dealers, not on one exchange, so its candles carry no volume and the bars would all be zero. That is why this page shows bitcoin from Hyperliquid instead.

Does volume change after a candle closes?

No. Once a candle has closed its bar is fixed. The candle that is still forming keeps growing as trades arrive, and its colour can flip until the close.

Related: On Balance Volume, Volume Weighted Moving Average, Money Flow Index, Chaikin Money Flow, every indicator.