What was the name of Japan’s speculative boom whose collapse began the country’s long asset-price downturn in 1990?

Japan’s speculative boom whose collapse began the country’s long asset-price downturn in 1990 was the Japanese asset price bubble.

During the late 1980s, Japanese land and share prices rose dramatically amid easy credit, financial speculation, and optimistic expectations. The Nikkei 225 reached its record closing level of 38,915.87 on 29 December 1989. The Bank of Japan then tightened monetary policy, and asset prices began to fall.

The decline damaged banks, companies, and households because much lending was secured against inflated land values. Falling collateral and bad loans weakened the financial system and contributed to years of slow growth and deflation.

The phrase “Lost Decade” usually describes the economic stagnation that followed, not the bubble itself. The bubble’s collapse is therefore the more precise answer to a question about the speculative boom and its stock-market downturn.