Trading volume refers to the number of shares or contracts of a given financial security traded during a specified period. It measures how actively a stock, currency pair, or other tradable instrument is being bought and sold.
Trading volume is an important indicator of liquidity and investor interest in a particular asset.
High trading volume shows a large number of participants actively buying and selling a given financial asset or tradable instrument. It implies that the market is very liquid, making it easy for investors to execute trades. Bid/ask spreads for high-volume securities are usually narrower.
In contrast, low trading volume suggests more limited interest and potential illiquidity, making trading more challenging and bid/ask spreads wider.
Volume is often displayed alongside price charts, providing a visual representation of market activity.
Traders need to understand trading volume because it offers insights into the strength and validity of price movements. For instance, a significant price surge accompanied by high volume suggests strong conviction behind the move, indicating that it’s likely to continue.
However, a price increase with low volume might be a sign of weak participation, potentially leading to a reversal. Similarly, during a downtrend, increasing volume confirms the selling pressure, while decreasing volume might signal a potential rebound of an asset’s price.
How does trading volume work?
Trading volume is the count of the number of shares or contracts of a given security exchanged during a specific period. This volume of data is tracked and published by stock exchanges and financial data providers.
Volume can be assessed over various periods ranging from one hour to one year. Common reference periods include daily, weekly, monthly, quarterly and annual trading volumes. Trading volumes on shorter timeframes, like one hour or five minutes, is also published by some providers
Daily trading volume is one of the most-watched measures and includes all shares traded during normal market hours. After-hours and pre-market trading volumes may also be reported separately.
What is trading volume used for?
Traders use volume to gauge the liquidity of a market. High liquidity, indicated by high volume, allows for easier entry and exit from trades, reducing the risk of slippage. Conversely, low liquidity can lead to wider spreads and make it difficult to execute trades at desired prices.
Additionally, volume can reveal areas of accumulation or distribution. Accumulation occurs when large players, such as institutional investors, are quietly buying a stock, often leading to increased volume without a significant price rise.
Distribution occurs when large players are selling their holdings, leading to increased volume without a significant price decline.
Recognizing these patterns can help traders anticipate future price movements, enable them to assess the conviction behind price movements, confirm chart patterns, and gauge market liquidity.
An indicator of market liquidity
If you’re buying a stock or any security, it’s important to know if it has high liquidity, because that makes it easier to buy and later sell the security.
On the other hand, low trading volume indicates low liquidity, which can make it difficult to execute. If an illiquid stock drops and you want to exit your position, a stock with low liquidity will be more difficult to sell at a certain price point.
A measure of market sentiment
Trading volume can be an early indicator of how the market thinks about a particular security or sector. A rising volume usually precedes a big move by the stock, either up or down.
A technical chart analysis tool
Volume plays a critical role in confirming chart patterns. Breakouts from consolidation patterns, such as triangles or flags, are considered more reliable when accompanied by a surge in volume. Without confirming volume, a breakout might be a false signal, leading to losses.
How is trading volume calculated?
At its core, trading volume is simply a tally of transactions occurring on the market, rather than a derived value.
Still, some calculations utilize trading volume data. For example, dividing a security’s total dollar value of shares traded by its price gives the raw volume figure.
Trading volume is often expressed as a percentage relative to a security’s shares outstanding, known as the public float. This normalized volume measure is called turnover, and it is used to compare the trading volume of individual securities to identify which ones are more active.
Additionally, technical analysts may calculate moving averages and volatility metrics based on trading volume data to identify trends and extremes.
Three examples of trading volume calculations
Trading volume, a measure of how much of an asset is traded, can be calculated in several ways, depending on the market and the desired metric. Let’s explore three common approaches:
1. Exchange-based volume
This method focuses on the total number of shares or contracts exchanged within a specific timeframe.
Example 1: You buy 50 shares of Johnson & Johnson stock in the morning and sell all of the shares the same day. Your total trading volume would be 100 shares.
Example 2: Let’s say you purchase 50 shares of Apple but sell 100 shares of Pfizer. Then another trader buys 100 shares of Apple, including the 50 you sold. That investor then sells 40 shares of Amazon. To calculate the total trade volume, it’s 150 (Apple) + 50 Pfizer + 40 Amazon for a total of 240 shares.
2. Tick-based volume
The method, commonly used in over-the-counter forex markets, looks at the number of price changes in a given period. In many forex trading platforms, a “pip” (percentage in point) is a common tick measurement.
A pip is 0.0001 for the EUR/USD forex pair. If we choose a particular time interval, such as two minutes, and during that interval, we track every time the price of the EUR/USD pair moves by at least 0.0001 pips, we get the tick-based volume.
If the price moved by 0.0001 pips a total of 60 times, the tick volume for those two minutes would be 60. Similarly to tick-based volume, in cryptocurrencies, traders often look at base or quote volume.
3. Trade count (Quantitative volume)
This approach measures the number of trades executed within a set period. It provides insights into the mentality of trading, but doesn’t consider the size of individual trades. So, a large single order could inflate the trade count.
Pros and cons of analyzing trading volume
Pros
- Gauging liquidity and investor interest for a specific security
- Confirming price trend strength
- Identifying reversals earlier
- Spotting unusual activity
- Assessing market breadth health
Cons:
- Limited predictive power
- Averages may differ widely across various securities
- It is prone to manipulation, especially if the market is relatively illiquid or prices are too low
What factors shape trading trading volume?
Several factors contribute to increased trading volume, particularly in US markets, including the growing prevalence of high-frequency traders and index funds. These passive investors use algorithmic trading, significantly boosting overall trading volume.
A study by Grand View Research forecasts a compound annual growth rate of 12.9% through the end of the decade in global algo trading, from $12.6 billion in 2024.
Retail traders who make decisions based on their own market analysis account for only about 10% of the total trading volume in US markets. These traders also often incorporate trading volume as a key element in their technical analysis.
Conclusion
Assessing trading volume levels provides clues about evolving market participation and sentiment. While not a precise timing tool alone, trading volume complements other indicators and techniques for analyzing securities.
Comparing real-time and historical volume statistics sheds light on emerging opportunities as well as lurking risks.
