Stocks & Commodities V. 25:4 (78-79): Momentum Indicators and Market Cycles by John Nicholas
Here’s an article we originally published 23 years ago, two years after Technical Analysis of STOCKS & COMMODITIES broke ground, proving that, yes, cycles are enduring.
The techniques used for stock and commodity analysis range from the naïvely simple to the stunningly complex. Some are based on sound mathematical and philosophical principles while others border on witchcraft. This article discusses one major indicator and how it relates to price movement. We often hear the markets described as “overbought” or “oversold.” Usually “oscillators” are used to help define these conditions. These same “oscillators” were called “momentum” by Larry Williams. In statistics, they are termed “moving percentages,” “rate of change,” or “differencing.” All of these terms refer to basically the same mathematical procedure. We will use the term “differencing” for the remainder of the article.
As the name implies, differencing involves subtraction,
specifically the subtraction of a price some number of days in the past from the most recent price. If each day we were to subtract the closing price of some commodity 10 days in the past from today’s price we would be differencing over a 10-day interval. The number we would calculate would be both positive and negative and would tend to move from one extreme, through zero, and the other extreme, up and down in a rather regular pattern. The interval that is used in
differencing is very important. In order to illustrate how the length of the interval affects the behavior of this indicator, we’ll apply various intervals of differencing to one dataset.