How to Determine a Security Price's Percentage Rate of Change

by C. Taylor, studioD

A security price's rate of change is a measure of momentum, which indicates how much the price has changed between two points in time. The time-frame used can be virtually anything you prefer. For short-term changes, you might chose a day, week or month. For long-term changes you might assess a year or multiple years. Regardless of the time-frame, the calculation remains the same.

Get the current and historic price of the stock. The historic price can be as far back as you like. You can get these quotes from your stock broker, or websites such as, or

Subtract historic price from the current price. As an example, if stock ABC is trading at $80.00 per share, but was trading at $75.00 per share a week ago, then the difference would be $5.

Divide this difference by the historic price to calculation the rate of change. In the example, dividing $5 by $75.00 gives you a 0.0667 rate of change, or 6.67 percent.

About the Author

C. Taylor embarked on a professional writing career in 2009 and frequently writes about technology, science, business, finance, martial arts and the great outdoors. He writes for both online and offline publications, including the Journal of Asian Martial Arts, Samsung, Radio Shack, Motley Fool, Chron, Synonym and more. He received a Master of Science degree in wildlife biology from Clemson University and a Bachelor of Arts in biological sciences at College of Charleston. He also holds minors in statistics, physics and visual arts.

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