On what date did Japan's Nikkei 225 reach its bubble-era peak before the 1990 crash?

Japan's Nikkei 225 reached its bubble-era peak on December 29, 1989.

The index closed at 38,915.87, marking the high point of Japan's late-1980s asset-price bubble. Equity and land prices had surged during a period of easy credit, optimistic expectations, and rapid financial expansion. Japanese companies and banks were widely regarded as exceptionally strong, and investors assumed high valuations could continue.

The bubble began to unwind after the Bank of Japan raised interest rates and authorities tightened financial conditions. Stock prices fell during 1990, while commercial land prices also declined. The banking system later faced severe problems because loans had been secured against assets whose values had collapsed.

The Nikkei did not quickly return to its 1989 level. Japan experienced years of weak growth, deflation, corporate restructuring, and financial-sector stress, a period often called the Lost Decades. The 1989 peak is therefore a useful marker, but the crash was not a single-day event like Black Monday in 1987.