U.S. stocks are plunging in early trading after Britons voted to leave the European Union.

The Dow Jones Industrial Average plunged 610 points, or 3.39 percent, as investors reacted strongly to Britain's decision to leave the European Union.

Friday's sell-off marked the Dow's biggest drop in 10 months.

The Standard & Poor's 500 index fell 57 points, or 2.7 percent, to 2,056x. The Nasdaq composite sank 158 points, or 3.2 percent, to 4,751.

It was the biggest drop for U.S. stocks since September.

European markets fell even more. France's benchmark index lost 8 percent and Britain's fell 4 percent.

The British pound plummeted to a 31-year low.

Bond prices rose sharply. The yield on the 10-year Treasury note dropped to 1.56 percent from 1.75 percent a day earlier, a huge move.