The Nikkei 225 reached its record closing high on December 29, 1989, before Japan's 1990 stock-market crash.
The index closed that day at 38,915.87, after a spectacular rise during Japan's late-1980s asset-price bubble. Real-estate and equity prices had surged, supported by easy credit and optimistic expectations. When the bubble burst, Japanese shares began a long decline.
The Nikkei 225 is a price-weighted index of 225 major companies listed on the Tokyo Stock Exchange's Prime Market. Its level therefore reflects share prices rather than the total market value of its constituents in the same way a capitalization-weighted index does.
The 1989 peak became a landmark in financial history. The index did not regain that closing level for more than three decades, finally exceeding it in 2024.