The Nikkei 225’s peak is used to date the start of Japan’s asset price bubble crash.
The index reached an intraday high of 38,957.44 on December 29, 1989, at the height of Japan’s late-1980s asset boom. Land and share prices had risen dramatically, supported by easy credit, optimistic expectations, and financial practices that encouraged speculation.
After the peak, Japanese equities and property prices fell for years. Banks were left with large portfolios of bad loans, and the resulting balance-sheet problems contributed to prolonged economic stagnation. The period is often called Japan’s “Lost Decades,” although the economic history includes several distinct phases.
The Nikkei 225 was not Japan’s only important benchmark: the broader TOPIX also recorded a major peak in 1989. The Nikkei is the commonly cited reference because its December 29 high provides a precise marker for the market’s reversal.