Japan's Nikkei 225 reached its all-time closing high on December 29, 1989, before the country's asset-price crash.
The Nikkei closed at 38,915.87 on the final trading day of 1989. The record came after a spectacular rise in Japanese share and land prices during the 1980s, when easy credit and optimistic expectations helped drive asset valuations far above sustainable levels.
The Bank of Japan raised interest rates beginning in 1989, and policymakers also moved to restrain property lending. As financial conditions tightened, equity and real-estate prices fell. The Nikkei then entered a prolonged decline, while banks faced large losses tied to property and corporate loans.
Japan's later period of weak growth and deflation is often called the "Lost Decades," although the timing and causes are more complicated than a single crash. The 1989 record is a closing value, not an intraday high; the index's intraday peak was slightly higher on the same date.