What name is given to the speculative boom and crash in Japanese stocks and property prices around 1990?

The speculative boom and crash in Japanese stocks and property prices around 1990 is called the Japanese asset price bubble.

During the second half of the 1980s, Japan experienced rapidly rising land and share prices. Easy credit, optimistic expectations, and financial deregulation helped push valuations to extraordinary levels. The Nikkei 225 reached its peak of 38,957.44 on December 29, 1989.

The bubble then burst as the Bank of Japan tightened monetary policy and asset prices began falling. Property values declined for years, while banks were left with large volumes of bad loans. The resulting economic stagnation is commonly associated with Japan’s “Lost Decades,” a broader period that followed the initial crash.

The term does not describe only a stock-market event: Japanese commercial land and residential property were central parts of the speculation, making this a combined asset-price bubble.