Barometer

Unlike the tool which measures atmospheric pressure, in finance, a barometer refers to markers or points of data designed to signify general economic or market trends. The Dow Jones Industrial Average and S&P 500 are well-known barometers of market health. They more or less are market health.

Data trends outside of market indexes can also serve this function. After the Great Recession of 2008, average revenues for companies providing non-essential consumer goods and services fell, indicating consumers were tightening their respective belts, mostly around their stomachs.