Worries about slowing economic growth in China, rising political uncertainty in Greece, and uncertainty about plans to raise U.S. interest rates shook investors and sparked a global stock sell-off on Friday.
Major U.S. indexes were down by three percent or more at Friday's close, Europe fell around three percent, and key Asian indexes were off sharply.
Concerns about faltering growth in the world's second-largest economy also pushed down prices for oil and other commodities, with crude costs falling below $40 per barrel for a while, a new six-year low.
China's surging economy has been an engine of global growth for the past 10 years, as break-neck expansion provided a market for energy, commodities, services, and other goods.
Shrinking industrial sector
But a new report shows China's huge industrial sector shrinking at the fastest rate in six years. Investors were already on edge because of turmoil in China's stock market and a surprise devaluation of the nation's currency.
Investors' mood was darkened by further political uncertainty in Greece, as the ruling party called a snap election for next month.
Some investors sought the safety of U.S. Treasury bonds, other bought gold, a traditional safe haven for money in troubled times. Gold and bond prices rose.
The eurozone and Japan have the most to lose from troubles in the developing world, according to a new study.
Wells Fargo Bank experts say economic growth in emerging markets has made them larger overall and a more important part of the economic process in wealthy nations over the past 20 years