Stocks closed sharply lower on Monday as investors grappled with the economic implications of Britain's vote to leave the European Union.

The sell-off followed the market's plunge on Friday, a day after the UK's referendum put the nation on course to exit the EU. The British pound fell further as traders expected the British economy to suffer because of the "leave" vote. Also Monday Standard & Poor's stripped the country of its top-shelf credit rating.

On Monday:

The Dow Jones industrial average sank 260.51 points, or 1.5 percent, to 17,140.24.

The Standard & Poor's 500 slid 36.87 points, or 1.8 percent, to 2,000.54.

The Nasdaq composite lost 113.54 points, or 2.4 percent, to 4,594.44.

For the year:

The Dow is down 284.79 points, or 1.6 percent.

The S&P 500 is down 43.40 points or 2.1 percent.

The Nasdaq is down 412.97 points, or 8.3 percent.