Describe its method roughly (you may not say it completely, you learned it yourself): when the green column begins to shorten, it means that the decline is over and it is about to rise. You can buy when the green column becomes shorter and keep it until the red column appears and becomes shorter, which means you can sell when the red column becomes shorter-"Buy when the green column becomes shorter" If you use DIFF and DEA ("yellow and white line") at the same time, you can judge the price trend more accurately, and "buy at the lowest point and sell at the highest point" (high throwing and low sucking) can do well.
If "MACD three+three theory" is combined with "periodic consistency theory", its accuracy and power in judging trends, especially "head" or "bottom", will be even more beyond imagination.
(There are free downloads of "Buying Up, Selling Down and Futures Trading Skills" and "MACD 3+3 Theory", please find it and learn to use it)