The indicator was developed by Gerald Appel, who first used it in 1979. The indicator is used in technical analysis. The MACD indicator is called trending because it is formed on two moving averages. They are not displayed on the instrument chart itself - only their parameters are taken into account in the calculations. The readings of the indicator itself are displayed in a separate window below the chart. This practically turns out to be a trend oscillator.
The classic MACD version contains a histogram of vertical bars with an additional smoothing line. The histogram reflects the distance between the moving averages and demonstrates the dynamics of their convergence or divergence. If the distance between the moving averages increases, the histogram bars also lengthen. If the distance decreases, then the columns are also shortened. When they line up above the zero lines and lengthen, it is generally assumed that the price will rise. When the bars of the histogram is below the zero lines and shorten, the price is expected to decline.