In Volume Oscillator Confirms Price Movement we looked at the measurement of volume by way of an oscillator using two moving averages. In this article we look at the volume rate of change (V-ROC), and we'll focus on the importance of price movements and volume in the study of market trends.

In the last decade, we've seen triple-digit swings on the Dow Jones Industrial Index to both the upside and the downside. A newcomer to the science of technical analysis may not have realized that some of these moves lacked conviction, as volume didn't always support the price movement. Chartists are not the least bit interested in a 5 to 10% move in a stock price if the volume moving the price is a fraction of the normal daily volume for that particular issue. On the other hand, since the Nasdaq market volume reaches or surpasses two billion shares per day, significant price action will trigger the interest of analysts. If price movements are significantly less than 5 to 10%, you might as well go golfing.

Volume Trend Indicator
The volume rate of change is the indicator that shows whether or not a volume trend is developing in either an up or down direction. You may be familiar with price rate of change (discussed here), which shows an investor the rate of change measured by the issue's closing price. To calculate this, you need to divide the volume change over the last n-periods (days, weeks or months) by the volume n-periods ago. The answer is a percentage change of the volume over the last n-periods. Now, what does this mean? If the volume today is higher than n-days (or weeks or months) ago, the rate of change will be a plus number. If volume is lower, the ROC will be minus number. This allows us to look at the speed at which the volume is changing. (For more on trend strength, check out ADX: The Trend Strength Indicator.)

One of the problems that analysts have with the V-ROC is determining the period of time to measure the rate of change. A shorter period of 10 to 15 days, for example, would show us the peaks created by a sudden change, and, for the most part, trendlines could be drawn. For a more realistic look, I would suggest using a 25- to 30-day period; this length of time makes the chart look more rounded and smooth. Shorter periods tend to produce a chart that is more jagged and difficult to analyze.

Figure 1: Volume Rate of Change - 14-Day Period
Chart Created with Tradestation

In the chart of the Nasdaq Composite Index, you can see a classic sell-off with the V-ROC reaching a high of 249.00 on December 13, 2001 (based on a 14-day period). In fact, if you study the chart closely, you can see that the ROC becomes positive for the first time on Dec 12, 2001, with a measurement of 19.61. On the next day the measurement jumps to 249.00 on the closing. The Nasdaq, however, had a high of 2065.69 on December 6 (ROC, +8.52) and then fell to negative numbers until December 12. By using a 14-day period, we cannot recognize this slide until the Index loses 119.18 points (approx. 6.5%) to the level of 1946.51. This would confuse most, were it not for the ability to change our period of time, in this case, to a 30-day period, shown in Figure 2.

Figure 2: Volume Rate of Change - 30-Day Period
Chart Created with Tradestation

In the second chart of the Nasdaq Composite Index, which uses a 30-day period, you can clearly see that in and around December 12 and 13, 2001, the ROC barely shows a positive number, and it is not until January 3, 2002 that a positive number appears, as the price action rises substantially from 1987.06 to 2098.88. On the ninth of the month, there is a move to the upside of 111.82 points. This positive value means there is enough market support to continue to drive price activity in the direction of the current trend. A negative value suggests there is a lack of support, and prices may begin to become stagnant or reverse.

We can see that even with a 14-day period, the V-ROC over the year shown on this chart, for the most part, moves quietly above and below the zero line. This indicates that there is no real conviction for there to be a trending market. The only real jump in price action that most investors missed is the move in late July, occurring over a period of five trading days, which, as you can see in the chart, has given almost everything back. Another interesting point is the lack of volume behind the price action as it moves upward. This is evident in the period from August 5, 2002, when the Nasdaq closed at 1206.01, to Aug 22, 2002, when the index closed at 1422.95. During this time, the V-ROC remained negative, indicating to all technical analysts that the increasing price in the index would not hold.

The Bottom Line
Using the previous volume indicators, you can confirm price movements that have conviction and avoid buying or selling based on blips in the market that will soon be corrected. Watch the volume, and the trends will follow. Remember it's your money - invest it wisely.

Related Articles
  1. Investing

    Asset Manager Ethics: Acting With Competence and Diligence

    Managers must make investment decisions based on their personal investment process, which in turn should be based on solid research and due diligence.
  2. Chart Advisor

    2 Short-Term and 2 Longer-Term Trade Ideas

    Two shorter-term and two longer-term trade ideas to consider, based on trends and the possibility of a breakout.
  3. Chart Advisor

    ChartAdvisor for November 27 2015

    Weekly technical summary of the major U.S. indexes.
  4. Professionals

    The Best Financial Modeling Courses for Investment Bankers

    Obtain information, both general and comparative, about the best available financial modeling courses for individuals pursuing a career in investment banking.
  5. Investing

    Where the Price is Right for Dividends

    There are two broad schools of thought for equity income investing: The first pays the highest dividend yields and the second focuses on healthy yields.
  6. Chart Advisor

    Pay Attention To These Stock Patterns Playing Out

    The stocks are all moving different types of patterns. A breakout could signal a major price move in the trending direction, or it could reverse the trend.
  7. Chart Advisor

    Now Could Be The Time To Buy IPOs

    There has been lots of hype around the IPO market lately. We'll take a look at whether now is the time to buy.
  8. Investing

    10 Cheap Vacations for the Ultimate Foodie

    If you are a foodie then explore one of these destinations in 2016.
  9. Chart Advisor

    Copper Continues Its Descent

    Copper prices have been under pressure lately and based on these charts it doesn't seem that it will reverse any time soon.
  10. Technical Indicators

    Using Pivot Points For Predictions

    Learn one of the most common methods of finding support and resistance levels.
  1. Can working capital be too high?

    A company's working capital ratio can be too high in the sense that an excessively high ratio is generally considered an ... Read Full Answer >>
  2. What are some of the most common technical indicators that back up Doji patterns?

    The doji candlestick is important enough that Steve Nison devotes an entire chapter to it in his definitive work on candlestick ... Read Full Answer >>
  3. How do I use discounted cash flow (DCF) to value stock?

    Discounted cash flow (DCF) analysis can be a very helpful tool for analysts and investors in equity valuation. It provides ... Read Full Answer >>
  4. Tame Panic Selling with the Exhausted Selling Model

    The exhausted selling model is a pricing strategy used to identify and trade based off of the price floor of a security. ... Read Full Answer >>
  5. Point and Figure Charting Using Count Analysis

    Count analysis is a means of interpreting point and figure charts to measure vertical price movements. Technical analysts ... Read Full Answer >>
  6. What assumptions are made when conducting a t-test?

    The common assumptions made when doing a t-test include those regarding the scale of measurement, random sampling, normality ... Read Full Answer >>

You May Also Like

Hot Definitions
  1. Cyber Monday

    An expression used in online retailing to describe the Monday following U.S. Thanksgiving weekend. Cyber Monday is generally ...
  2. Bar Chart

    A style of chart used by some technical analysts, on which, as illustrated below, the top of the vertical line indicates ...
  3. Take A Bath

    A slang term referring to the situation of an investor who has experienced a large loss from an investment or speculative ...
  4. Black Friday

    1. A day of stock market catastrophe. Originally, September 24, 1869, was deemed Black Friday. The crash was sparked by gold ...
  5. Turkey

    Slang for an investment that yields disappointing results or turns out worse than expected. Failed business deals, securities ...
  6. Barefoot Pilgrim

    A slang term for an unsophisticated investor who loses all of his or her wealth by trading equities in the stock market. ...
Trading Center