The Nikkei 225's record closing level before Japan's asset-price bubble burst was 38,915.87, reached on 29 December 1989.
The peak came at the end of a spectacular Japanese asset boom. During the second half of the 1980s, rising land and share prices, easy credit, and strong optimism pushed Japanese asset valuations to extraordinary levels. The Nikkei 225, Japan's leading share index, climbed from its 1980s lows to an all-time closing high on the final trading day of 1989.
The bubble then deflated. Japanese share prices fell sharply during 1990, while real-estate values continued declining over subsequent years. The Nikkei's 1989 peak became a defining reference point for Japan's “lost decades,” although the economic causes and timeline were more complicated than a single stock-market collapse. A common mix-up is the intraday high: the index reached 38,957.44 during trading on 29 December, but its closing record was lower, at 38,915.87.