Japan experienced the Nikkei 225’s historic peak before the early-1990s asset-price crash.
The Nikkei 225 reached an intraday high of 38,957.44 on December 29, 1989. The peak came after a powerful Japanese asset-price bubble in which land and share prices rose dramatically, supported by easy credit, optimistic expectations, and strong economic confidence.
The bubble then burst. Japanese equities declined sharply, while commercial land values also fell for many years. The resulting period is often called Japan’s Lost Decade, although economic weakness and deflation extended beyond the 1990s in several respects.
The Nikkei’s 1989 peak is a useful benchmark, but it is not the same as the crash’s lowest point. The index continued falling after 1990 and reached a long-term low in October 2008 during the global financial crisis. Questions about the “highest level” should therefore specify whether they mean the intraday or closing record.