 Business cycle, the business cycle, also known as the economic cycle or trade cycle, is the downward and upward movement of gross domestic product GDP around its long-term growth trend. The length of a business cycle is the period of time containing a single boom and contraction in sequence. These fluctuations typically involve shifts over time between periods of relatively rapid economic growth expansions or booms and periods of relative stagnation toward decline contractions or recessions. Business cycles are usually measured by considering the growth rate of real gross domestic product. Despite the often applied term cycles, these fluctuations in economic activity do not exhibit uniform or predictable periodicity. The common or popular usage boom and bust cycle refers to fluctuations in which the expansion is rapid and the contraction severe.