Stocks are plunging in the US and worldwide after the UK voted to leave the European Union.
The result stunned investors who reacted by rushing to the safety of gold and US government bonds as they wondered what will come next for Britain, Europe and the global economy.
US stocks took far smaller losses than markets in Europe and Asia, but were still sharply lower in morning trading. The Dow Jones industrial average was down 378 points, or 2.1%, to 17,631. It was down as much as 538 points earlier
The S and P 500 is on pace for its biggest loss since January, down 48 points, or 2.3%, to 2,064. The Nasdaq composite dropped 134 points, or 2.7%, to 4,775.
Britons voted to leave the EU over concerns including immigration and regulation. It is far from clear what that will mean for international trade or for Europe, as the EU, which was formed in the decades following the Second World War, has never before lost a member state.
The vote brought a massive dose of uncertainty to financial markets, something investors loathe. Traders responded by dumping riskier assets that appeared to have the most to lose from disruptions in financial flows and trade: banks, technology companies and makers of basic materials.
The vote will start years of negotiations over Britain's trade, business and political links. Observers wonder if other nations will follow in Britain's footsteps by leaving the EU.
"This entire process is going to take a long time," said David Kelly, chief global strategist at JPMorgan Asset Management. "This is a negative in economic terms for the UK. The EU will be very tough negotiators with them."
Banks took the largest losses by far. Citigroup plummeted 3.61 dollars, or 8.1%, to 40.85 dollars and Bank of America fell 79 cents, or 5.6%, to 13.25 dollars.
Technology stocks also took hefty losses. Microsoft fell 1.26 dollars, or 2.4%, to 50.65 dollars and IBM gave up 5.71 dollars, or 3.7%, to 149.64 dollars.
Banks have the most to lose in Britain's departure from the EU as they do a lot of cross-border business in Europe based from their offices in London.
Safety assets soared. Gold jumped 51 dollars, or 4%, to 1,315 dollars an ounce. Newmont Mining rose the most in the S&P 500 index. It gained 2.08 dollars, or 5.9%, to 37.47 dollars. The price of silver climbed 41 cents, or 2.4%, to 17.77 dollars an ounce.
Investors also bought utility company stocks and left phone companies basically unchanged while other parts of the market took big losses. Duke Energy rose 82 cents, or 1%, to 82.87 dollars and Consolidated Edison gained 1.45 dollars, or 1.9%, to 78.31 dollars while Verizon added 32 cents to 55 dollars.
The Federal Reserve said it is carefully monitoring financial markets and cooperating with central banks overseas.
Investors had sent stocks higher this week as they gradually grew more confident, based on polls and the changing odds in the betting market, that Britain would stay in the EU. They sent the pound to its highest price of the year and sold bonds, pushing their yields higher.
Those gains were rapidly undone Friday as the euro tumbled and the pound plunged to a 31-year low, while bond yields hit some of their lowest levels of the year and gold surged to a two-year high.
Britain's FTSE 100 plunged as much as 8% but recovered much of its losses later, falling 1.9%. The German index sank 5.6% and France's index tumbled 6.5%.
The pound hit its lowest level since 1985 before recovering slightly to trade at 1.3648 dollars. That's still far below the 1.4808 dollars it traded late on Thursday in New York.
Oil prices fell sharply. Benchmark US crude lost$2.14 dollars, or 4.2%, to 48 dollars a barrel in New York. Brent crude, the international benchmark, fell 2.29 dollars, or 4.5%, to 48.62 dollars a barrel in London.
"This will be an act of economic self-harm with global ramifications," said Samuel Tombs, chief UK economist at Pantheon Macroeconomics.
It could also threaten London's position as one of the world's pre-eminent financial centres as professionals could lose the right to work across the EU. The UK hosts more headquarters of non-EU firms than Germany, France, Switzerland and the Netherlands put together.
Japan's Nikkei 225 finished the wild day down 7.9%, its biggest loss since the global financial crisis in 2008. South Korea's Kospi sank 3.1%, its worst day in four years. Hong Kong's Hang Seng index tumbled 4.4% and stocks in Shanghai, Taiwan, Sydney, Mumbai and Southeast Asian countries were sharply lower.
In other currencies, the dollar fell to 102.16 yen from 104.47 yen while the euro weakened to 1.1117 dollars from 1.1351 dollars.