Kondratiev Wave
Description
Investopedia:
" Kondratiev Wave is a long-term economic cycle in commodity prices and other prices, believed to result from technological innovation, that produces a long period of prosperity alternating with economic decline. This theory was founded by Nikolai D. Kondratiev (also spelled "Kondratieff"), an agricultural economist who noticed agricultural commodity and copper prices experienced long-term cycles. Kondratiev believed that these cycles involved periods of evolution and self-correction." (https://www.investopedia.com/terms/k/kondratiev.asp)