Want to know what experienced traders are doing even when the market seems quiet? 

The Negative Volume Index (NVI) might be the key! This unique tool tracks price changes when the trading volume is low, helping you uncover potential trends that others might miss.

Why does the NVI matter? It lets you spot subtle shifts in market sentiment, potentially signaling upcoming changes in price direction. This can give you an edge in identifying trades that others don’t see yet.

This article will cover everything you need to know about the NVI, including how it works and what it reveals, signals to spot potential trend changes, and strategies to use the NVI effectively. Ready to unlock a new layer of market insight? Let’s dive into the NVI!

Exploring the Negative Volume Index (NVI)

The Negative Volume Index, or NVI for short, is a unique financial tool. It analyzes price changes on lower-volume days, offering a different perspective than indicators focused on high-volume trading. Unlike those, NVI sheds light on big-time investor activity during quieter market periods. While the NVI is valuable, traders often use it alongside other technical analysis tools, like looking at the bid-ask spread, for a more comprehensive market understanding.

Historically, the NVI was created by Paul Dysart in the 1930s to understand how smart money slowly gathered or sold off positions without much attention from most people. Later on, Norman Fosback in the 1970s made this idea better known and provided a detailed way of calculating and understanding it through his book called Stock Market Logic. He suggested that investors who are not well-informed or less sophisticated usually make trades on days when there is a lot of noise and high volume, but the more knowledgeable investors do their trading on calm days, which often results in visible patterns that help to forecast where the market will go.

Understanding stock volume is crucial, and the NVI offers a unique perspective compared to traditional volume-based indicators like On-Balance Volume or Positive Volume Index. NVI specifically focuses on price changes during low-volume days, potentially revealing price increases less noticeable with regular indicators. A rising NVI suggests price increases even when overall trading volume is low, possibly indicating stealthy buying by informed investors. Conversely, a falling NVI could signal those insiders selling shares during quiet periods, potentially foreshadowing a market downturn. 

To comprehend the NVI is important for traders wishing to add to their analysis by gaining a sense of how powerful market participants could be quietly affecting stock prices, giving them an advantage in predicting where the market will go next.

Mechanics of the Negative Volume Index

The Negative Volume Index (NVI) works on a basic but very deep idea: it looks only at the days when trading volume has gone down compared to the day before. The main thought is that, when there are fewer shares being traded, decisions by big investors or those who know more can greatly affect stock prices and might show trends that are not easy to see.

The workings of the NVI are simple but they work well. This index begins with a chosen starting number, usually 1000, and changes happen only on days when fewer shares are traded compared to the day before. When the closing price today is more than yesterday, we increase the NVI by how much percentage the price changed. But if the close price goes down, we do not change the NVI because it means that on days when not many shares are traded, and prices drop, it’s less important since big investors are likely not involved.

Paying attention to days when there is less trading helps the NVI remove the distractions that happen because of investors who don’t have much information and trade a lot. This way, it might give better hints about where prices will go in the future. The NVI works well in markets that are moving clearly in one direction because understanding the main force or changes can be very helpful for making plans. It is also useful in markets where the patterns of volume and the actions of investors do not match with what we usually expect, giving us understanding that could be missed by other indicators of volume.

To summarize, the NVI assists people who trade in spotting possible shifts in the market that come from actions by knowledgeable investors on days when trading is not very loud or obvious. This can be very useful for noticing the beginning of a new direction in prices or seeing if an ongoing trend will keep going, offering traders a better position to make choices.

Decoding the NVI

Grasping the meanings from Negative Volume Index (NVI) signals is very important for traders who want to use its ability to predict in less active market moments. Mostly, NVI pays attention to times when fewer shares are traded than before, this usually means that knowledgeable investors and big financial organizations are making moves.

When the NVI goes up, it often means that on days when not many shares are traded, the prices still go higher. This might show that people who know a lot about trading are buying more of the stock because they believe its price will keep going up. If this rise in NVI happens regularly for some time, it could be taken as a positive sign, indicating an ongoing trend where the stock price may continue to climb.

On the other hand, if the NVI is not going up or it’s going down – and this drop usually happens when there is a big fall in prices on days with not much trading – it can mean that the clever investors are not really trusting the stock price right now, which might suggest that prices will stay the same or go down. But because NVI doesn’t go down on those days when more shares are traded, even if prices do decline, having an unchanged NVI while prices are dropping could sometimes give you the wrong idea. Traders should be cautious and consider other indicators to confirm the trend.

To effectively interpret the NVI:

  • Search for a continuous increase in the NVI to see signs of possible upward trends. This growth usually comes before the wider market notices and might give chances to enter into long positions early on.
  • Watch for a constant or decreasing NVI while looking at other market signals to spot possible sell points or verify if the trend is going down.
  • Mix the movements of NVI with trends in volume and also use other methods for technical analysis like moving averages or indicators for momentum to make sure the signals are correct. For example, if NVI is going up at the same time as a moving average crossover happens, it could make the signal to buy.

By analyzing these signals with attention, traders can use the NVI to make decisions that are based on knowledge during calm market times. They take advantage of movements that may not be seen by people who just watch changes in price and volume when there is a lot of activity. This detailed way lets them put buy or sell orders early before big movements happen in the wider market, giving an advantage in their trading approach.

Calculating the NVI

The Negative Volume Index (NVI) is a technical indicator concerning volume that helps to know the impact of days with less trading volume compared to the prior day on stock prices. This NVI looks at days when there’s not so much trading, following the idea that clever investors make their moves in a more discreet way.

Step-by-Step Calculation of NVI:

  • NVI begins with an initial value, commonly established at 1000 to simplify the process of calculating and contrasting it across different periods.
  • For every day of trade, look at the volume of trading and see how it is different from the volume on the day before. NVI gets a new calculation only if today’s volume is smaller than yesterday’s.
  • To calculate NVI, if the volume today is less than what it was yesterday, then change NVI based on how much the price has changed. Here is the equation to use:

Image of the NVI formula

If today’s volume is not lower, the NVI remains unchanged from the previous day.

Example Calculation – Assume:

  • Day 1 closing price = $100, NVI = 1000
  • Day 2 closing price = $102, volume decreases compared to Day 1

Calculate the price change ratio:

  • 102 – 100 / 100 = 0.02 (2%)

Apply the NVI formula:

  • NVI  = 1000 + (0.02 × 1000) = 1020
  • Thus, the NVI for Day 2 is 1020.

The NVI does not change on days when volume increases, underscoring its focus on ‘quiet’ days. Traders track the NVI over time to detect trends in the behavior of informed or institutional investors, especially during less noticeable market movements. By understanding and calculating the NVI, traders can better gauge potential market direction influenced by sophisticated market participants on days with reduced volume, potentially leading to more informed trading decisions.

Applying the NVI in Trading Strategies

The Negative Volume Index, or NVI for short, is a particular instrument made to spot early signs of how the market is moving. It does this by looking at days when there are fewer trades compared to yesterday. This special way of observing can be very useful for traders who want to use the calm times in the market to predict big changes.

Trend Confirmation:

  • The NVI works well for showing trends when the market is not too unstable. If the NVI keeps going up, it usually means that the smart investors who know a lot are carefully buying more during times when fewer shares are traded, which might confirm that prices are generally increasing.
  • On the other hand, if the NVI keeps going down regularly, it might mean that knowledgeable traders are slowly leaving their trades, which could suggest that a downward trend is coming soon.

Buy and Sell Signals:

  • When NVI goes up and prices are also increasing, it might be a signal to buy. This can mean that experienced investors are active in the market on days when there is less noise.
  • When NVI goes down while prices also decrease, it might be a sign to sell because knowledgeable investors seem not to have much trust, making the negative market feeling stronger.


  • Traders must pay attention to the differences between NVI and how prices change. When NVI goes up and the price does not follow, this difference might show that there is a growing force upwards, maybe before we can see an increase in the market clearly.
  • Likewise, when the price goes up but the NVI does not go with it, this could mean that knowledgeable investors are not behind the price rise, signaling there might be a future adjustment or change in the price direction.

To add the NVI into a trading plan, you need to do more than just watch the index. It’s important to use it together with other measures that confirm its signals. For example, you could match the NVI with indicators linked to volume such as the average directional index, or even classic methods like moving averages for stronger analysis support. This approach with many dimensions makes sure that traders can check the signals given by the NVI, making their choices better in different situations of the market.

By adding the NVI to a trade plan, people who do trading can make use of less busy but still meaningful days for trades. When they look at what the knowledgeable investors are doing at these times, traders might understand possible changes in the market before these changes show up on usual indicators.

Illustrating the NVI Through Examples

To show how useful the Negative Volume Index (NVI) can be, let’s look at a true example with the S&P 500 ETF (SPY) and its response to important events in the market.

Initial Scenario: As the Federal Reserve was getting ready to make its announcement on May 1, 2024, traders were preparing for a very important change in Fed-day movement that had not been seen since last year; this is what Citi analysts suggested. The NVI looks at days when fewer shares are traded and it reacted strongly as people waited with great interest for the news.

Middle stage: Opposite to what some people in the market were thinking, the Feds chose to keep rates steady. Because of this choice, there was a small fall in the S&P 500, which you can see on the SPY price chart. During this time, the NVI showed that informed investors were not buying a lot on days when fewer shares were traded. This means that smart people in the market might be careful or thinking prices will go down.

Here’s the SPY in action: 

Two-week graph of the S&P 500 ETF showing recent price movements.

S&P 500 ETF Two-Week Price Chart

Later Developments: Although it started with a small drop, the SPY succeeded in having its first day of gains after three days of losing. The NVI indicated a minor increase suggesting that knowledgeable investors were starting to recognize worth and purchase shares during times when general trading volume was low.


The situation with the SPY shows that NVI is an important tool for investors. It gives information that other common indicators do not show. NVI looks at how much stocks informed investors are buying when there is not a lot of trading happening. This way, it reveals feelings about the market that people might miss normally. This might be especially helpful in markets that are unstable or not sure, where the usual signs of how much is being traded may not completely show the subtle ways investors act.

Pros and Cons

The Negative Volume Index, or NVI, is a special instrument in technical analysis. It pays attention mainly to the stock price changes on days when there’s less trading volume than the day before. This method gives understanding that is not the same as usual indicators based on volume and brings both benefits and restrictions for trading activities.


  • Concentration on calm days: The distinctive approach of the NVI is to center attention specifically on days when there’s less trading activity. This strategy helps traders understand the feelings of investors who think long-term and tend not to react every day, but only when big changes happen in the market. It can be very helpful for noticing new trends early, before most other people see them.
  • Early signs of trend shifts: NVI usually can spot possible changes before many other indicators. It ignores the distractions from days with lots of trading, so it gives a better view when investors start to feel differently about the current market direction.
  • When you use the NVI together with other market indicators, it gives more layers to your analysis. Especially when checking signals that arise from big changes in volume which are seen in usual indicators such as On-Balance Volume (OBV).


  • In markets with high historical volatility and wide fluctuations in trading volume, the NVI might be less reliable. This is because its core insights are derived from those less active periods, which become less frequent in highly volatile markets.
  • Because the NVI does not consider days when a lot of shares are traded, it can overlook big changes in the market that happen on such days. This means there could be wrong ideas about which way the market is going if someone only uses this indicator by itself.
  • Delayed Signals: Sometimes the NVI might give signals later because it looks for less trading volume to make sure a trend is real. This could miss quick chances in markets or unexpected financial happenings.

The Negative Volume Index (NVI) offers a nuanced approach to analyzing volume by focusing on quieter trading days to discern investor sentiment and underlying market strength. It provides valuable insights, particularly useful for detecting early signs and movements in subdued markets. However, traders should be aware that its effectiveness diminishes in highly volatile markets. Integrating the NVI with other analytical methods and using investment alerts for balance enables traders to maximize the benefits of the NVI while mitigating its limitations. This balanced approach helps traders effectively harness the NVI’s potential while managing associated risks. 


The Negative Volume Index (NVI) acts as an advanced instrument for those who analyze charts and trade, providing a special viewpoint by only looking at price changes on days when volume is lower. This method gives a better insight into the true feelings of the market and what investors with information are doing, which can sometimes be hidden during busier times.

While NVI is strong for foreseeing market trends over a long time, traders must use it together with other technical tools and indicators, such as Bollinger Bands. This combination is important because it confirms signals and makes the trading chances found by NVI more trustworthy.

The effective use of the Negative Volume Index relies on how well a trader understands its signs in relation to overall market conditions and changes in price movement. Traders who do this can take advantage of NVI for better decision-making, but they should also be aware of its restrictions to steer clear of usual mistakes when using it.

Negative Volume Index: FAQs

How Does the Negative Volume Index Differ from Typical Volume Analysis?

The Negative Volume Index (NVI) pays attention only to times when the amount of trading is less than the day before. It’s different from usual ways that look at changes in both number of trades and prices every day because NVI cares more about calm days on the market, thinking this is when traders who know a lot are doing their work.

What are the Primary Signals to Look for When Using the NVI?

Traders ought to search for important changes or patterns in the NVI line. When NVI is going up, it means the market could be getting stronger on days with less trading volume, and people usually see this as a good sign, especially when the NVI goes higher than its average movement. Conversely, a declining NVI can signal bearish conditions.

Is the NVI Suitable for Use in Different Market Varieties, Including Stocks, Forex and Commodities?

Certainly, the NVI is usable in different market areas like stocks, forex and goods. But how well it works can change with each market’s liquidity and unique volume trends. It’s most useful in markets where volume fluctuations provide significant insight into investor sentiment.

What are the Common Pitfalls When Interpreting the NVI?

Many people make the mistake of spending too much on NVI. They do this without checking with additional indicators, which can result in false market signals. This happens often in markets that change quickly and where volume does not always go together with price changes. Traders can sometimes misunderstand the NVI signals if they ignore the wider context of the market.

How Often Should the NVI Be Recalculated for Optimal Trading Performance?

The NVI needs to be recalculated every day because it is made to show changes that come from daily volume data. Updating often makes sure the indicator shows the latest conditions and feelings in the market. The number of times recalibration is needed could vary based on how long the trading strategy lasts and what the trader requires.