On Black Monday — October 19, 1987 — the Dow fell 22.6% in a single day, still its worst one-day percentage drop ever. No single piece of news fully explains it.

In the 2010 "Flash Crash," the U.S. stock market lost roughly a trillion dollars of value in minutes — then recovered most of it before the day was over.

The first great stock bubble burst three centuries ago. In 1720 shares of Britain’s South Sea Company shot from around £100 to nearly £1,000 in a matter of months, then collapsed back toward £100 by year-end — ruining thousands of investors.

Japanese stocks compounded at roughly 17% a year through the 1970s and nearly 29% a year through the 1980s — turning $10,000 in 1970 into about $610,000 by 1989. The bubble then burst so completely that the Nikkei 225 didn’t reclaim its December 1989 peak until February 2024, a 35-year round trip.