Volume spike
A day when the number of shares traded is far above the recent average.
What it shows
Volume is the number of shares traded in a bar. A spike is a bar where volume is at least twice its 50-bar average. It shows unusual activity.
Spikes often come with news, earnings or a big price move. The spike says that many shares changed hands. It does not say who was buying or selling.
How we find it
The same code that draws it on your chart follows these steps, with the same result every time.
- Compute the 50-bar average volume.
- For each bar, ratio = volume ÷ average.
- Mark bars where the ratio is 2 or more.
- Show the ratio.
Starting values: Average 50 bars; Spike 2× average. These are proposed and will be tuned on real price data before launch.
How to read it
- Bars under the price are volume.
- The gold bar is the spike.
- The dashed line is the average.
Status labels you may see
| Label | What it means |
|---|---|
| Spike today | Volume is at least 2× the 50-bar average. |
| Spike recently | A spike in the last 5 bars. |
| Normal | No spike. |
What cancels it
Nothing cancels it.
What traders check next
- The direction and size of the price bar.
- What news came out.
- Whether volume stays high after.
Limits
- Volume can be high for many reasons.
- Index rebalancing days create spikes.
- 2× is a convention.
Try it in forecastviz
- Open any ticker and choose Volume and money flow → Volume spike in the left menu.
- Switch between 3M, 6M to see how the picture changes.
- Compare with Volume climax and Volume dry-up on the same chart.
Questions
Does a spike mean buyers won?
No. For every buyer there is a seller.
Why 50 bars?
About two months of trading.
Related trends
Further reading
- Murphy, Technical Analysis of the Financial Markets
- Granville, Granville's New Key to Stock Market Profits
- Pring, Technical Analysis Explained
- Achelis, Technical Analysis from A to Z
Educational only. Not financial advice, and not a price forecast. Charts are drawn by code from past price data, which may be delayed.