History·13 February 2026·4 min read
Black Monday 1987 — when computers crashed the market
In a single day, the US market lost over 22%. Partly to blame: automated trading programs.
On October 19, 1987, "Black Monday", the US market fell over 22% in one day — the largest single-session percentage drop in history.
Machines that sell on their own
A new cause appeared: automated programs that sold by themselves when prices fell, accelerating the collapse. It was the first sign that technology can amplify market panic — an ever more relevant lesson.
