What Is Negative Volume Index (NVI)?

The Negative Volume Index (NVI) integrates volume and price to demonstrate how price movements are affected by days with declining volume. Learn about its meaning, calculation, significance, and application in financial markets.

Negative Volume Index (NVI): Meaning, Calculation, and Application in Financial Markets

The Negative Volume Index (NVI) is a technical analysis tool used by traders and analysts to assess the relationship between trading volume and price movements in financial markets. The NVI focuses on days when the trading volume is lower than the previous day’s volume, illustrating how price movements are influenced by decreasing volume.

Calculation of Negative Volume Index (NVI)

Formula for NVI

The NVI is calculated using the following formula:

$$ NVIt = \begin{cases} NVIt-1 + \left(\frac{P_t - P_{t-1}}{P_{t-1}}\right) \times NVIt-1 & \text{if } V_t < V_{t-1} \\ NVIt-1 & \text{if } V_t \geq V_{t-1} \end{cases} $$

Where:

  • \( NVIt \) is the Negative Volume Index at time \( t \).
  • \( P_t \) is the price at time \( t \).
  • \( P_{t-1} \) is the price at time \( t-1 \).
  • \( V_t \) is the volume at time \( t \).
  • \( V_{t-1} \) is the volume at time \( t-1 \).

Step-by-Step Calculation

  • Base NVI Calculation:

    • Start with an initial NVI value, often set at 1000.
  • Determine Volume Changes:

    • Compare the current day’s trading volume with the previous day’s volume.
  • Update NVI:

    • If the current day’s volume is less than the volume on the previous day, update the NVI using the given formula.
    • If the volume is equal to or greater than the previous day’s volume, the NVI remains unchanged.

Significance of Negative Volume Index (NVI)

Market Insight

The NVI is particularly significant as it provides insight into how market prices react on days with lower trading volumes. It assumes that smart money (institutional investors) is more active on low-volume days. Thus, significant price movements on these days could indicate underlying trends and investor sentiment.

Traders often use the NVI in conjunction with other indicators to confirm market trends. An increasing NVI suggests that the price is likely to rise even on lower volume days, potentially revealing a bullish trend. Conversely, a decreasing NVI may indicate a bearish trend.

Applications of Negative Volume Index (NVI)

Portfolio Management

Investors use NVI to manage their portfolios by identifying underlying bullish or bearish trends. It helps in making informed decisions regarding asset allocation and risk management.

Technical Analysis

Technical analysts utilize the NVI to support or refute signals derived from other indicators. It acts as a supplementary tool to validate market movements and establish more robust trading strategies.

Historical Context and Development

The Negative Volume Index was introduced by Paul Dysart in the 1930s. Dysart’s work pioneered the concept of volume-based market indicators, which has since evolved into a crucial aspect of technical analysis.

Positive Volume Index (PVI)

Unlike the NVI, the Positive Volume Index (PVI) focuses on days when the trading volume is higher than the previous day’s volume. It assumes that uninformed investors drive market prices on high volume days.

On-Balance Volume (OBV)

The On-Balance Volume (OBV) indicator is another volume-based tool that accumulates volume to predict price movements. Unlike NVI, OBV considers all trading days regardless of volume changes.

FAQs

How is the NVI different from traditional volume analysis?

NVI specifically zeroes in on days with declining volume, offering unique insights that traditional volume analysis might overlook.

Can NVI be used for all asset classes?

While commonly applied to stocks, the NVI can be adapted for other asset classes like commodities and forex, provided volume data is available.

Does NVI work well with other technical indicators?

Yes, the NVI is often used alongside other technical indicators to provide a comprehensive analysis of market trends.

References

  1. Murphy, John J. Technical Analysis of the Financial Markets. New York Institute of Finance, 1999.
  2. Dysart, Paul. The Study and Analysis of Volume. 1930.

Summary

The Negative Volume Index (NVI) is an essential tool in technical analysis, providing insight into price movements on days with decreased volume. By understanding and utilizing the NVI, traders and analysts can gain a deeper look into market trends, making more informed decisions in portfolio and risk management.

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