In 1936, Paul L. Dysart, Jr. began accumulating two series of advances and declines distinguished by whether volume was greater or lesser than the prior day's volume. He called the cumulative series for the days when volume had been greater than the prior day's volume the Positive Volume Index (PVI), and the series for the days when volume had been lesser the Negative Volume Index (NVI).
A native of Iowa, Dysart worked in Chicago's LaSalle Street during the 1920s. After giving up his Chicago Board of Trade membership, he published an advisory letter geared to short-term trading using advance-decline data. In 1933, he launched the Trendway weekly stock market letter and published it until 1969 when he died. Dysart also developed the 25-day Plurality Index, the 25-day total of the absolute difference between the number of advancing issues and the number of declining issues, and was a pioneer in using several types of volume of trading studies. Richard Russell, editor of Dow Theory Letters, in his January 7, 1976 letter called Dysart "one of the most brilliant of the pioneer market technicians."[1]
Dysart’s NVI and PVI
The daily volume of the New York Stock Exchange and the NYSE Composite Index's advances and declines drove Dysart's indicators. Dysart believed that “volume is the driving force in the market.” He began studying market breadth numbers in 1931, and was familiar with the work of Leonard P. Ayres and James F. Hughes, who pioneered the tabulation of advances and declines to interpret stock market movements.
Dysart calculated NVI as follows: 1) if today's volume is less than yesterday's volume, subtract declines from advances, 2) add the difference to the cumulative NVI beginning at zero, and 3) retain the current NVI reading for the days when volume is greater than the prior day's volume. He calculated PVI in the same manner but for the days when volume was greater than the prior day's volume. NVI and PVI can be calculated daily or weekly.
Initially, Dysart believed that PVI would be the more useful series, but in 1967, he wrote that NVI had “proved to be the most valuable of all the breadth indexes.” He relied most on NVI, naming it AMOMET, the acronym of “AMeasure Of Major Economic Trend.”
Dysart's theory, expressed in his 1967 Barron's article, was that “if volume advances and prices move up or down in accordance [with volume], the move is assumed to be a good movement - if it is sustained when the volume subsides.” In other words, after prices have moved up on positive volume days, "if prices stay up when the volume subsides for a number of days, we can say that such a move is 'good'." If the market “holds its own on negative volume days after advancing on positive volume, the market is in a strong position.”
He called PVI the “majority” curve. Dysart distinguished between the actions of the “majority” and those of the “minority.” The majority tends to emulate the minority, but its timing is not as sharp as that of the minority. When the majority showed an appetite for stocks, the PVI was usually “into new high ground” as happened in 1961.
It is said that the two indicators assume that "smart" money is traded on quiet days (low volume) and that the crowd trades on very active days. Therefore, the negative volume index picks out days when the volume is lower than on the previous day, and the positive index picks out days with a higher volume.
Dysart’s Interpretation of NVI and PVI
Besides an article he wrote for Barron's in 1967, not many of Dysart's writings are available. What can be interpreted about Dysart's NVI is that whenever it rises above a prior high, and the DJIA is trending up, a “Bull Market Signal” is given. When the NVI falls below a prior low, and the DJIA is trending down, a “Bear Market Signal” is given. The PVI is interpreted in reverse. However, not all movements above or below a prior NVI or PVI level generate signals, as Dysart also designated “bullish” and “bearish penetrations.” These penetrations could occur before or after a Bull or Bear Market Signal, and at times were called “reaffirmations” of a signal. In 1969, he articulated one rule: “signals are most authentic when the NVI has moved sideways for a number of months in a relatively narrow range.” Dysart cautioned that “there is no mathematical system devoid of judgment which will continuously work without error in the stock market.”
According to Dysart, between 1946 and 1967, the NVI “rendered 17 significant signals,” of which 14 proved to be right (an average of 4.32% from the final high or low) and 3 wrong (average loss of 6.33%). However, NVI “seriously erred” in 1963-1964 and in 1968, which concerned him. In 1969, Dysart reduced the weight he had previously given to the NVI in his analyses because NVI was no longer a “decisive” indicator of the primary trend, although it retained an “excellent ability to give us ‘leading’ indications of short-term trend reversals.”
A probable reason for the NVI losing its efficacy during the mid-1960s may have been the steadily higher NYSE daily volume due to the dramatic increase in the number of issues traded so that prices rose on declining volume. Dysart’s NVI topped out in 1955 and trended down until at least 1968, although the DJIA moved higher during that period. Norman G. Fosback has attributed the “long term increase in the number of issues traded” as a reason for a downward bias in a cumulative advance-decline line. Fosback was the next influential technician in the story of NVI and PVI.
Fosback’s Variations
Fosback studied NVI and PVI and in 1976 reported his findings in his classic Stock Market Logic. He did not elucidate on the indicators’ background or mentioned Dysart except for saying that “in the past Negative Volume Indexes have always [his emphasis] been constructed using advance-decline data….” He posited, “There is no good reason for this fixation on the A/D Line. In truth, a Negative Volume Index can be calculated with any market index - the Dow Jones Industrial Average, the S&P 500, or even ‘unweighted’ market measures.... Somehow this point has escaped the attention of technicians to date.”
The point had not been lost on Dysart, who wrote in Barron’s, “we prefer to use the issues-traded data [advances and declines] rather than the price data of any average because it is more all-encompassing, and more truly represents what’s happening in the entire market.” Dysart was a staunch proponent of using advances and declines.
Fosback made three variations to NVI and PVI:
1. He cumulated the daily percent change in the market index rather than the difference between advances and declines. On negative volume days, he calculated the price change in the index from the prior day and added it to the most recent NVI. His calculations are as follows:
If Ct and Cy denote the closing prices of today and yesterday, respectively, the NVI for today is calculated by
adding NVIyesterday (Ct - Cy) / Cy to yesterday's NVI if today's volume is lower than yesterday's, adding zero otherwise,
and the PVI is calculated by:
adding PVIyesterday (Ct - Cy) / Cy to yesterday's PVI if today's volume is higher than yesterday's, adding zero otherwise.
2. He suggested starting the cumulative count at a base index level such as 100.
3. He derived buy or sell signals by whether the NVI or PVI was above or below its one-year moving average.
Fosback's versions of NVI and PVI are what are popularly described in books and posted on Internet financial sites. Often reported are his findings that whenever NVI is above its one-year moving average there is a 96% (PVI - 79%) probability that a bull market is in progress, and when it is below its one-year moving average, there is a 53% (PVI - 67%) probability that a bear market is in place. These results were derived using a 1941-1975 test period. Modern tests might reveal different probabilities.
Today, NVI and PVI are commonly associated with Fosback's versions, and Dysart, their inventor, is forgotten. It cannot be said that one version is better than the other. While Fosback provided a more objective interpretation of these indicators, Dysart's versions offer value to identify primary trends and short-term trend reversals.
Although some traders use Fosback's NVI and PVI to analyze individual stocks, the indicators were created to track, and have been tested, on major market indexes. NVI was Dysart's most invaluable breadth index, and Fosback found that his version of “the Negative Volume Index is an excellent indicator of the primary market trend.” Traders can benefit from both innovations.
Related Research Articles
The Dow Jones Industrial Average (DJIA), Dow Jones, or simply the Dow, is a stock market index of 30 prominent companies listed on stock exchanges in the United States.
A stock market crash is a sudden dramatic decline of stock prices across a major cross-section of a stock market, resulting in a significant loss of paper wealth. Crashes are driven by panic selling and underlying economic factors. They often follow speculation and economic bubbles.
A market trend is a perceived tendency of the financial markets to move in a particular direction over time. Analysts classify these trends as secular for long time-frames, primary for medium time-frames, and secondary for short time-frames. Traders attempt to identify market trends using technical analysis, a framework which characterizes market trends as predictable price tendencies within the market when price reaches support and resistance levels, varying over time.
In finance, technical analysis is an analysis methodology for analysing and forecasting the direction of prices through the study of past market data, primarily price and volume. As a type of active management, it stands in contradiction to much of modern portfolio theory. The efficacy of technical analysis is disputed by the efficient-market hypothesis, which states that stock market prices are essentially unpredictable, and research on whether technical analysis offers any benefit has produced mixed results. It is distinguished from fundamental analysis, which considers a company's financial statements, health, and the overall state of the market and economy.
The Dow theory on stock price movement is a form of technical analysis that includes some aspects of sector rotation. The theory was derived from 255 editorials in The Wall Street Journal written by Charles H. Dow (1851–1902), journalist, founder and first editor of The Wall Street Journal and co-founder of Dow Jones and Company. Following Dow's death, William Peter Hamilton, Robert Rhea and E. George Schaefer organized and collectively represented Dow theory, based on Dow's editorials. Dow himself never used the term Dow theory nor presented it as a trading system.
In stock and securities market technical analysis, parabolic SAR is a method devised by J. Welles Wilder Jr., to find potential reversals in the market price direction of traded goods such as securities or currency exchanges such as forex. It is a trend-following (lagging) indicator and may be used to set a trailing stop loss or determine entry or exit points based on prices tending to stay within a parabolic curve during a strong trend.
MACD, short for moving average convergence/divergence, is a trading indicator used in technical analysis of securities prices, created by Gerald Appel in the late 1970s. It is designed to reveal changes in the strength, direction, momentum, and duration of a trend in a stock's price.
This article is a summary of the closing milestones of the Dow Jones Industrial Average, a United States stock market index. Since first closing at 62.76 on February 16, 1885, the Dow Jones Industrial Average has increased, despite several periods of decline.
The Dogs of the Dow is an investment strategy popularized by Michael B. O'Higgins in a 1991 book and his Dogs of the Dow website.
On-balance volume (OBV) is a technical analysis indicator intended to relate price and volume in the stock market. OBV is based on a cumulative total volume.
The commodity channel index (CCI) is an oscillator originally introduced by Donald Lambert in 1980.
Volume–price trend (VPT) is a technical analysis indicator intended to relate price and volume in the stock market. VPT is based on a running cumulative volume that adds or subtracts a multiple of the percentage change in share price trend and current volume, depending upon the investment's upward or downward movements.
The McClellan oscillator is a market breadth indicator used in technical analysis by financial analysts of the New York Stock Exchange to evaluate the balance between the advancing and declining stocks. The McClellan oscillator is based on the Advance-Decline Data and it could be applied to stock market exchanges, indexes, portfolio of stocks or any basket of stocks.
The average directional movement index (ADX) was developed in 1978 by J. Welles Wilder as an indicator of trend strength in a series of prices of a financial instrument. ADX has become a widely used indicator for technical analysts, and is provided as a standard in collections of indicators offered by various trading platforms.
The advance–decline line is a stock market technical indicator used by investors to measure the number of individual stocks participating in a market rise or fall. As price changes of large stocks can have a disproportionate effect on capitalization weighted stock market indices such as the S&P 500, the NYSE Composite Index, and the NASDAQ Composite index, it can be useful to know how broadly this movement extends into the larger universe of smaller stocks. Since market indexes represent a group of stocks, they do not present the whole picture of the trading day and the performance of the market during this day. Though the market indices give an idea about what has happened during the trading day, advance/decline numbers give an idea about the individual performance of particular stocks.
The US bear market of 2007–2009 was a 17-month bear market that lasted from October 9, 2007 to March 9, 2009, during the financial crisis of 2007–2009. The S&P 500 lost approximately 50% of its value, but the duration of this bear market was just below average.
The Advance-Decline data also known as AD data are calculated to show the number of advancing and declining stocks and traded volume associated with these stocks within a market index, stock market exchange or any basket of stocks with purpose of analysis of the sentiment within the analysed group of stocks. Advance-Decline data are used to measure overall market breadth as well as to measure sentiment within the stock market sectors.
The 2015–2016 stock market selloff was the period of decline in the value of stock prices globally that occurred between June 2015 to June 2016. It included the 2015–2016 Chinese stock market turbulence, in which the SSE Composite Index fell 43% in just over two months between June 2015 and August 2015, which culminated in the devaluation of the yuan. Investors sold shares globally as a result of slowing growth in the GDP of China, a fall in petroleum prices, the Greek debt default in June 2015, the effects of the end of quantitative easing in the United States in October 2014, a sharp rise in bond yields in early 2016, and finally, in June 2016, the 2016 United Kingdom European Union membership referendum, in which Brexit was voted upon.
Jason Goepfert is an American researcher and columnist focused on the development of behavioral finance. Prior to founding Sundial Capital Research, he was the manager of back office operations for Deephaven Capital Management, a Minnesota-based hedge fund, and Wells Fargo's online brokerage unit.
Volume Analysis is an example of a type of technical analysis that examines the volume of traded securities to confirm and predict price trends. Volume is a measure of the number of shares of an asset that are traded in a given period of time. As one of the oldest market indicators used for analysis, sudden changes in volume are often the result of news-related events. Commonly used by chartists and technical analysts, volume analysis is centered on the following ideas:
References
↑ Russell, Richard, ''Dow Theory Letters'', Jan. 7, 1976 (no. 652); see also ''Dow Theory Letters'' nos. 638, 642, and 646
Appel, Gerald, Winning Market Systems, pp.42–44, Windsor Books, Bridgewaters, New York (1989)
Dysart, Jr., Paul L., "Bear Market Signal?: A Sensitive Breadth Index Has Just Flashed One", Barron's (Sept. 4, 1967)
Fosback, Norman G., Stock Market Logic: A Sophisticated Approach to Profits on Wall Street, pp.120–124, Deaborn Financial Printing, Chicago, Illinois (1993)
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
