The crisis that drove the Athens Stock Exchange General Index down by more than 80% was the Greek debt crisis.
Greece’s crisis became acute after revelations that earlier public-finance data had understated the country’s deficits. Investors then demanded higher interest rates on Greek government debt, while concerns spread about public borrowing, banking stability, and the future of the euro area.
The Athens market fell heavily as recession, austerity measures, political uncertainty, and restructuring fears damaged corporate expectations. From its 2007 high to its 2012 low, the Athens Stock Exchange General Index lost more than 80%.
The crisis involved international rescue programs organized by the European Union and International Monetary Fund, alongside major fiscal reforms. It is often described as part of the wider European sovereign-debt crisis, but Greece was its most prominent early case. The market decline was not simply a single-day crash; it was a prolonged collapse across several years.