Sine Wave

DEFINITION of 'Sine Wave'

An geometric waveform that oscillates (moves up, down or side-to-side) periodically, and is defined by the function y = sin x. In other words, it is an s-shaped, smooth wave that oscillates above and below zero.


The Composite Index of Lagging Indicators, one of three Business Cycle Indicators published by the Conference Board is known to resemble a sine wave since the measures that make up the index (i.e. ratios and interest rates) tend to oscillate between a range of values. For example, inflation is always kept between specified rates and if/once inflation meets or exceeds a specified limit, interest rates will be adjusted to either increase or decrease inflation so it is brought within a target range. Thus, as the rate of inflation increases, decreases or stays the same, interest rates will oscillate up and down to control an undesired rate of inflation.