Iceland experienced the world's largest one-day stock-market percentage fall during the 2008 crisis, when its main stock index dropped 76.13% on October 14, 2008.
The collapse followed the failure of Iceland's highly leveraged banking model. The country's three largest banks—Glitnir, Landsbanki, and Kaupthing—had expanded rapidly using international funding, but global credit markets froze after the wider financial crisis intensified.
The Icelandic stock exchange suspended trading in October 2008, and the financial sector was placed under extraordinary government supervision. The index's dramatic fall reflected both the collapse of listed bank shares and the removal of financial companies from the index.
This figure is often described as a single-day stock-market crash, but it should not be compared directly with the Dow's 22.6% percentage loss in 1987 without considering market composition and index changes.