The Nikkei 225 fell 14.9% on October 20, 1987, Japan’s trading day after Black Monday hit the United States.
The 1987 crash moved across time zones. Asian markets reacted to the previous session’s collapse in New York, and Japan’s Nikkei 225 recorded a historically severe one-day decline. European and North American markets had already experienced major losses as investors sold shares globally.
Japan was then in an extraordinary asset-price boom. Land and share prices had risen sharply during the late 1980s, supported by easy credit and optimistic expectations. The 1987 international crash did not immediately end Japan’s boom, which continued until the Nikkei reached its peak near the end of 1989.
The 14.9% figure refers specifically to the Nikkei’s one-day percentage decline on October 20, 1987. It should not be confused with the Dow’s 22.6% fall on October 19 or with Japan’s much longer asset-price collapse in the early 1990s.