Orders and trading · updated October 21, 2026
What is a stock's trading volume and why does it matter
Volume shows how many shares changed hands over a period, usually one day. High volume means many buyers and sellers, so you can get in and out easily, at prices close to the one shown.
Trading volume formula
- Volume
- The number of shares traded in the period. Every share sold is also bought, so it is counted once.
- Value traded
- Volume in money. It is more useful for comparisons, because share prices differ a lot.
Worked example
In one day, 200,000 shares of a company traded at an average price of $25.
If you want to buy $10,000 worth, you are 0.2% of the day's volume: you will not move the price.
How to read trading volume
Volume is best read against its average over the last 20-50 days. A day with three times the average volume usually signals news or new interest.
When trading volume can fool you
Special days: when indices change their members or options expire, volume jumps without any news about the company. Low price, high volume: a million shares at $0.10 is only $100,000.
Related terms
Learn it in the Academy
Questions about trading volume
What does high volume on a price rise mean?
That many investors are buying with conviction. A rise on low volume is more fragile and can reverse easily.
Where do I see volume?
On the chart, below the prices, as vertical bars. Our stock pages also show the average volume.
These explanations are for information only. They are not a recommendation to buy or sell.
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