Analysts said the so-called Brexit generated massive "uncertainty" that killed the appetite for stocks. No one knows what happens next as the entire U.K. — including England, Scotland, Wales and Northern Ireland — pulls away from the EU.
For decades, the U.K. has been one of the most powerful members of the EU, which encompasses more than a half-billion people doing business in a free trade zone covering 28 countries. So the loss of this key member raises complicated questions about trade relationships and economic stability.
The ultimate impact of Brexit will play out slowly as terms of the "divorce" emerge. But based on what we know now, here are some losers — and yes, winners.
People who invested earlier this week. No matter what shares you bought on Wednesday, you probably lost money by Friday. In Japan, the Nikkei stock average fell nearly 8 percent, marking the single worst trading day since 2011. The STOXX Europe 600 Index dropped about 7 percent. In the U.S., the Nasdaq composite index of stocks fell 4.12 percent; the Dow Jones industrial average dropped 3.39 percent.
Savers hoping for higher interest payouts. Overwhelmingly, economists now say the Federal Reserve won't raise interest rates this year. Brexit is seen as an immense setback for global growth; the central bank can't pile on the misery.
Companies pumping oil. Since spring, oil prices have been rising. The price of a barrel of West Texas Intermediate crude oil, which had dropped below $30 in February, had clawed its way back to nearly $52 this month. But with the global economy looking shakier, the price has slumped back down to $47.61.
Businesses in poorer countries. Currencies in emerging markets — from Mexico to Hungary to South Africa — plunged in value as investors fled riskier assets. When your country has a weak currency, you can't afford the imports you need to grow, such as Caterpillar tractors and Ford trucks.
British tourists coming to the U.S. The British pound plummeted after the Brexit vote, down nearly 8 percent to $1.37 — the lowest level since 2009. That means U.K. residents planning trips to Orlando had better figure on eating sandwiches in their rooms; their vacation costs have just jumped higher.
Homebuyers seeking cheap mortgages. The Brexit vote is pushing interest rates to record lows. So investors in safer U.S. mortgage-backed securities will be plentiful, which means interest rates can remain at very low levels.
Procrastinators considering a refi. People who have been thinking about refinancing their debt but keep putting off the task can take heart. You now have more time to fill out those forms because interest rates are not likely to rise.
TTIP opponents. If you hate free trade deals, then Brexit will help you put a nail in the coffin of the Transatlantic Trade and Investment Partnership. The trade deal is being negotiated with U.S. and EU officials. But now EU negotiators are going to have their hands full working out a U.K. divorce. There are only so many hours in the day.
Supporters of the EU. OK, maybe this sounds crazy. But with economic chaos now enveloping the U.K., the remaining EU members may become more determined to pull together and make their joint project work better. Maybe they will cut back on the annoying bureaucracy and focus more on growth.
Smart cookies in the Silicon Valley. With interest rates so low and stock purchases looking risky, wealthy investors all over the world may see the United States as the best place to take chances on startup companies. They have to put their money someplace; the U.S. tech sector may be just the ticket.