The Nikkei 225’s 1989 peak is commonly used to mark the start of Japan’s asset-price crash.
The index reached an all-time intraday high of 38,957.44 on December 29, 1989. It then entered a long decline as Japan’s property and equity bubble burst. The boom had been supported by abundant credit, soaring land values, and expectations that asset prices would continue rising.
The crash became part of Japan’s “Lost Decades,” a period associated with weak growth, banking problems, deflationary pressure, and prolonged balance-sheet repair. The Nikkei’s fall was closely connected to the collapse in commercial and residential property prices.
The TOPIX is another important Japanese market index, but the Nikkei 225 is the specific benchmark most often cited for the 1989 peak. That distinction makes the index name important in this question.